[Android] AGP 9 / built-in Kotlin compatibility

[BriceFab]

Summary

Flutter apps are adopting AGP 9 with android.builtInKotlin=true and android.newDsl=true. Plugin Android modules that still apply the legacy Kotlin Gradle Plugin (org.jetbrains.kotlin.android) or rely on pre–AGP 9 Gradle DSL can break or conflict with host apps on the new toolchain.

Ask

Please plan migration of :permission_handler_android (and related Android Gradle) per Flutter’s guide for plugin authors:

https://docs.flutter.dev/release/breaking-changes/migrate-to-built-in-kotlin/for-plugin-authors

Context

• Ecosystem: flutter/flutter#184836
• Existing requests (#1513, #1484) are not scoped to AGP 9 / built-in Kotlin / new DSL; this issue is for that track.

Happy to help test with a prerelease.