[FSSDK-12872] Prepare for release android-sdk v5.3.0 (#537)

* Prepare for release android-sdk v5.3.0

- Bump java_core_ver from 4.4.2 to 4.5.0
- Update CHANGELOG with 5.3.0 entry (Local Holdouts, CMAB fixes)
- Update README dependency version to 5.3.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* clean up

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: muzahidul-opti

CHANGELOG.md

@@ -1,5 +1,22 @@
 # Optimizely Android X SDK Changelog
 
+## 5.3.0
+July 8, 2026
+
+### New Features
+
+**Local Holdouts**: Added support for Local Holdouts, enabling holdout experiments
+to be scoped to specific feature flags rather than applied globally.
+Local Holdouts let you measure the true incremental impact of individual features
+by holding out a subset of users from specific rollouts while still serving them other experiences.
+See [Holdouts docs](https://support.optimizely.com/hc/en-us/articles/38941939408269-Global-holdouts) for more information.
+- Upgrade dependency to [Java SDK 4.5.0](https://github.com/optimizely/java-sdk/releases/tag/4.5.0)
+
+### Fixes
+
+- Use attribute id instead of key for CMAB prediction requests
+- Normalize decision event campaign_id, variation_id, and entity_id
+
 ## 5.2.1
 May 29, 2026
 

README.md

@@ -32,7 +32,7 @@ repositories {
 }
 
 dependencies {
-	implementation 'com.optimizely.ab:android-sdk:5.2.1'
+	implementation 'com.optimizely.ab:android-sdk:5.3.0'
 }
 ```
 

build.gradle

@@ -97,7 +97,7 @@ ext {
     build_tools_version = "35.0.0"
     min_sdk_version = 21
     target_sdk_version = 35
-    java_core_ver = "4.4.2"
+    java_core_ver = "4.5.0"
     android_logger_ver = "1.3.6"
     jacksonversion= "2.11.2"
     annotations_ver = "1.2.0"