Feature/flutter 3.44 compatibility

[thearaks]

Fixes Android build issues with Flutter 3.44

[ncuillery]

The changes in Flutter 3.44 Android compilation caused a jvmTarget version ambiguity error. See https://docs.flutter.dev/release/breaking-changes/migrate-to-built-in-kotlin/for-plugin-authors

Flutter android compilation process is scanning both the java file and the kt file, causing the error described in #97

This PR fixes both issues, @yekeskin is it possible to move forward with it?

[ralatorre]

Independent confirmation: this exact set of changes (dropping the Kotlin copy of FlutterAvifPlugin, compileSdk 36, Java 17) is what we needed to build flutter_avif_android 3.1.0 in a production app on AGP 9.0.1 / Kotlin 2.3.20 with android.builtInKotlin=false. Debug and release builds are clean with no warnings, and encode output verified on a real device (Pixel 8a) decodes correctly.

Keeping the Java copy is also the more future-proof side to keep: Flutter now deprecates plugins that apply the Kotlin Gradle Plugin, and host apps that set android.builtInKotlin=false would not compile the Kotlin class at all without it.

[eschirni]

I encountered the same issue after upgrading my flutter SDK today. I would love to see this integrated in the real package

[martinogarrizzo5]

Is there any update? I also need this update, please!