Modernize Android build and app config for current Android SDKs

[Copilot]

This updates the project’s legacy Android setup so it can target current Android versions and align with modern Gradle/AGP requirements. It also adds the minimum manifest/runtime changes needed for newer platform behavior without changing game logic.

• Build system

  • Upgraded the Gradle wrapper to a current release
  • Reworked root/module build scripts to use modern Android plugin wiring and dependency configurations
  • Moved Java compilation to Java 11 for compatibility with current Android tooling
  • Removed obsolete module wiring that prevented the Android build from being the primary supported path

• Android target configuration

  • Raised compileSdk / targetSdk to 35
  • Increased minSdk to a modern supported floor
  • Added the Android namespace and version metadata in Gradle where current AGP expects it

• Manifest compatibility

  • Removed deprecated uses-sdk manifest configuration in favor of Gradle-owned SDK settings
  • Added android:exported="true" on the launcher activity for Android 12+
  • Kept the existing launcher/orientation behavior intact

• Runtime/network behavior

  • Added a scoped network security config to allow the game’s existing cleartext stats endpoint on modern Android
  • Preserved the keep-screen-on behavior and enabled immersive mode in the Android launcher

<activity
    android:name="com.mygdx.game.AndroidLauncher"
    android:exported="true"
    android:screenOrientation="landscape">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>