chore: update logback.xml

- Comment out old logback configuration
- Add note explaining the use of FlutterLogbackAppender for logging

Author: muzahidul-opti

android/src/main/assets/logback.xml

@@ -1,18 +1 @@
-<!-- <configuration
-    xmlns="https://tony19.github.io/logback-android/xml"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="https://tony19.github.io/logback-android/xml https://cdn.jsdelivr.net/gh/tony19/logback-android/logback.xsd"
->
-    <appender name="logcat" class="ch.qos.logback.classic.android.LogcatAppender">
-        <tagEncoder>
-            <pattern>Optimizely</pattern>
-        </tagEncoder>
-        <encoder>
-            <pattern>%msg</pattern>
-        </encoder>
-    </appender>
-
-    <root level="DEBUG">
-        <appender-ref ref="logcat" />
-    </root>
-</configuration> -->
+<!-- We do not use this since all logging is handled programmatically via FlutterLogbackAppender and forwarded to the Dart logger. -->