use colored backdrop for Input Screen alpha transitions on API 33+ (#6421)

Task/Issue URL:
https://app.asana.com/1/137249556945/project/1208671518894266/task/1210820490944337?focus=true

### Description
Uses the `backdrop` API for window transitions to supply a backdrop
color which is drawn below and beyond bounds of the activity to prevent
the activity window fading to black during alpha transitions.

I remove the translation transition from API < 31 because it didn't run
on tested devices anyway.

Additionally, I cleaned up the transition files and moved them to
`duckchat` module, which is more appropriate as they are targeted
specifically at the Input Screen transition behavior.

### Steps to test this PR

- [x] Verify the slide + fade transitions look right in light and dark
mode on API >= 33
- [x] Verify the fade transition looks right in light and dark mode on
API < 33 (unchaged behavior)

### UI changes (for API 33+)
| Before  | After |
| ------ | ----- |

![before](https://github.com/user-attachments/assets/92a492eb-f578-4217-b0c5-8e856e69d082)|![after](https://github.com/user-attachments/assets/a17161cb-e655-4ffc-b72e-0679a274db3c)|

Author: LukasPaczos

app/src/main/java/com/duckduckgo/app/browser/BrowserTabFragment.kt

@@ -246,7 +246,6 @@ import com.duckduckgo.browser.api.ui.BrowserScreens.PrivateSearchScreenNoParams
 import com.duckduckgo.browser.api.ui.BrowserScreens.WebViewActivityWithParams
 import com.duckduckgo.common.ui.DuckDuckGoActivity
 import com.duckduckgo.common.ui.DuckDuckGoFragment
-import com.duckduckgo.common.ui.anim.AnimationResourceProvider
 import com.duckduckgo.common.ui.experiments.visual.store.ExperimentalThemingDataStore
 import com.duckduckgo.common.ui.store.BrowserAppTheme
 import com.duckduckgo.common.ui.tabs.SwipingTabsFeatureProvider
@@ -288,6 +287,7 @@ import com.duckduckgo.downloads.api.DownloadsFileActions
 import com.duckduckgo.downloads.api.FileDownloader
 import com.duckduckgo.downloads.api.FileDownloader.PendingFileDownload
 import com.duckduckgo.duckchat.api.DuckChat
+import com.duckduckgo.duckchat.api.inputscreen.BrowserAndInputScreenTransitionProvider
 import com.duckduckgo.duckchat.impl.inputscreen.ui.InputScreenActivity.Companion.QUERY
 import com.duckduckgo.duckchat.impl.inputscreen.ui.InputScreenActivity.Companion.TAB_ID
 import com.duckduckgo.duckchat.impl.inputscreen.ui.InputScreenActivityParams
@@ -574,6 +574,9 @@ class BrowserTabFragment :
     @Inject
     lateinit var omnibarTypeResolver: OmnibarTypeResolver
 
+    @Inject
+    lateinit var browserAndInputScreenTransitionProvider: BrowserAndInputScreenTransitionProvider
+
     /**
      * We use this to monitor whether the user was seeing the in-context Email Protection signup prompt
      * This is needed because the activity stack will be cleared if an external link is opened in our browser
@@ -1075,8 +1078,8 @@ class BrowserTabFragment :
                 requireContext(),
                 InputScreenActivityParams(query = query),
             )
-            val enterTransition = AnimationResourceProvider.getSlideInFromTopFadeIn()
-            val exitTransition = AnimationResourceProvider.getSlideOutToBottomFadeOut()
+            val enterTransition = browserAndInputScreenTransitionProvider.getInputScreenEnterAnimation()
+            val exitTransition = browserAndInputScreenTransitionProvider.getBrowserExitAnimation()
             val options = ActivityOptionsCompat.makeCustomAnimation(
                 requireActivity(),
                 enterTransition,

common/common-ui/src/main/java/com/duckduckgo/common/ui/anim/AnimationResourceProvider.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2025 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.duckchat.api.inputscreen
+
+/**
+ * Provides animation resources for activity transitions between browser and input screen.
+ */
+interface BrowserAndInputScreenTransitionProvider {
+
+    fun getBrowserEnterAnimation(): Int
+
+    fun getBrowserExitAnimation(): Int
+
+    fun getInputScreenEnterAnimation(): Int
+
+    fun getInputScreenExitAnimation(): Int
+}

duckchat/duckchat-api/src/main/java/com/duckduckgo/duckchat/api/inputscreen/BrowserAndInputScreenTransitionProvider.kt

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,18 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@anim/overshoot_interpolator_tension_1">
+    android:backdropColor="@color/background_background_dark"
+    android:duration="@integer/slide_animation_duration_ms"
+    android:showBackdrop="true">
 
     <translate
         android:fromYDelta="56dp"
+        android:interpolator="@anim/overshoot_interpolator_tension_1"
         android:toYDelta="0dp" />
 
     <alpha
         android:fromAlpha="0.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="1.0" />
 
 </set>

common/common-ui/src/main/res/anim/slide_in_from_bottom_fade_in_overshoot.xml renamed to duckchat/duckchat-api/src/main/res/anim-v33/slide_in_from_bottom_fade_in_dark.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,18 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@anim/overshoot_interpolator_tension_1">
+    android:backdropColor="@color/background_background_light"
+    android:duration="@integer/slide_animation_duration_ms"
+    android:showBackdrop="true">
 
     <translate
-        android:fromYDelta="-56dp"
+        android:fromYDelta="56dp"
+        android:interpolator="@anim/overshoot_interpolator_tension_1"
         android:toYDelta="0dp" />
 
     <alpha
         android:fromAlpha="0.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="1.0" />
 
 </set>

common/common-ui/src/main/res/anim/slide_in_from_top_fade_in_overshoot.xml renamed to duckchat/duckchat-api/src/main/res/anim-v33/slide_in_from_bottom_fade_in_light.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,16 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@android:anim/decelerate_interpolator">
+    android:duration="@integer/slide_animation_duration_ms">
 
     <translate
         android:fromYDelta="-56dp"
+        android:interpolator="@anim/overshoot_interpolator_tension_1"
         android:toYDelta="0dp" />
 
     <alpha
         android:fromAlpha="0.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="1.0" />
 
 </set>

common/common-ui/src/main/res/anim/slide_in_from_top_fade_in.xml renamed to duckchat/duckchat-api/src/main/res/anim-v33/slide_in_from_top_fade_in.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,18 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@anim/overshoot_interpolator_tension_1">
+    android:backdropColor="@color/background_background_dark"
+    android:duration="@integer/slide_animation_duration_ms"
+    android:showBackdrop="true">
 
     <translate
         android:fromYDelta="0dp"
+        android:interpolator="@anim/overshoot_interpolator_tension_1"
         android:toYDelta="56dp" />
 
     <alpha
         android:fromAlpha="1.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="0.0" />
 
 </set>

common/common-ui/src/main/res/anim/slide_out_to_bottom_fade_out_overshoot.xml renamed to duckchat/duckchat-api/src/main/res/anim-v33/slide_out_to_bottom_fade_out_dark.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,18 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@anim/overshoot_interpolator_tension_1">
+    android:backdropColor="@color/background_background_light"
+    android:duration="@integer/slide_animation_duration_ms"
+    android:showBackdrop="true">
 
     <translate
         android:fromYDelta="0dp"
-        android:toYDelta="-56dp" />
+        android:interpolator="@anim/overshoot_interpolator_tension_1"
+        android:toYDelta="56dp" />
 
     <alpha
         android:fromAlpha="1.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="0.0" />
 
 </set>

common/common-ui/src/main/res/anim/slide_out_to_top_fade_out_overshoot.xml renamed to duckchat/duckchat-api/src/main/res/anim-v33/slide_out_to_bottom_fade_out_light.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,16 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@android:anim/decelerate_interpolator">
+    android:duration="@integer/slide_animation_duration_ms">
 
     <translate
         android:fromYDelta="0dp"
+        android:interpolator="@anim/overshoot_interpolator_tension_1"
         android:toYDelta="-56dp" />
 
     <alpha
         android:fromAlpha="1.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="0.0" />
 
 </set>

common/common-ui/src/main/res/anim/slide_out_to_top_fade_out.xml renamed to duckchat/duckchat-api/src/main/res/anim-v33/slide_out_to_top_fade_out.xml

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
+<?xml version="1.0" encoding="utf-8"?><!--
   ~ Copyright (c) 2025 DuckDuckGo
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,15 +15,11 @@
   -->
 
 <set xmlns:android="http://schemas.android.com/apk/res/android"
-    android:duration="300"
-    android:interpolator="@android:anim/decelerate_interpolator">
-
-    <translate
-        android:fromYDelta="56dp"
-        android:toYDelta="0dp" />
+    android:duration="@integer/slide_animation_duration_ms">
 
     <alpha
         android:fromAlpha="0.0"
+        android:interpolator="@android:anim/decelerate_interpolator"
         android:toAlpha="1.0" />
 
 </set>