feat: add Android 15 support and update dependencies

- Add Android 15 support
- Update AGP version to 8.7.0
- Update gradle version to 8.10.2
- Update kotlin version to 2.1.0

Author: muzahidul-opti

CHANGELOG.md

@@ -1,13 +1,13 @@
 # Optimizely Flutter SDK Changelog
 
 ## 3.1.0
-October 3rd, 2025
+October 6th, 2025
 
-### Functionality Enhancements
-* Android 15 support added ([#84](https://github.com/optimizely/optimizely-flutter-sdk/pull/84))
-	- Update AGP version to 8.7.0
-	- Update gradle version to 8.10.2
-	- Update kotlin version to 2.1.0
+This minor release added the following support:
+* Android 15 support ([#84](https://github.com/optimizely/optimizely-flutter-sdk/pull/84))
+* Update AGP version to 8.7.0
+* Update gradle version to 8.10.2
+* Update kotlin version to 2.1.0
 
 ## 3.0.1
 Jun 4th, 2025