Migrate Android implementation (rive_native) to Built-in Kotlin (AGP 9.0+ compatibility)

[BlindingTree]

Submission checklist

• I have confirmed the issue is present in the latest version of the rive Flutter package
• I have searched the documentation and forums and could not find an answer
• I have searched existing issues and this is not a duplicate

Description

I am using rive_native (via rive package) in my Flutter app and have encountered an issue with its Android build configuration.

Problem

The Android implementation (rive_native) applies the Kotlin Gradle Plugin (KGP) using apply plugin: "kotlin-android" in its build.gradle. Starting with AGP 9.0, this approach is deprecated and will cause build failures in future Flutter versions.

Current Issue

• Uses apply plugin: "kotlin-android" in the Android module
• Uses kotlinOptions (old syntax) instead of kotlin.compilerOptions (new syntax)

Required Changes in rive_native:

1. Remove apply plugin: "kotlin-android"
2. Replace kotlinOptions block with:

kotlin {
    compilerOptions {
        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
    }
}

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

Flutter issue #189133: https://github.com/flutter/flutter/issues/189133

Workaround
I'm keeping android.builtInKotlin=false in gradle.properties temporarily until this is resolved.

Please migrate the Android implementation to Built-in Kotlin to ensure your users can build their apps in future Flutter versions.

Thank you!

### Reproduction steps / code

The issue occurs during Android build when using `rive_native` as a dependency via the `rive` package.

### Upload your reproduction files / stack trace

_No response_

### Source `.riv` / `.rev` file

_No response_

### Screenshots / video

_No response_

### Rive Flutter package version

0.14.10

### Flutter version

Flutter 3.44.4 • channel [user-branch] • unknown source
Framework • revision 1234567890 (some hash)
Engine • revision 1234567890
Tools • Dart 3.9.0

### Device

Infinix X6731B (Android device)

### OS version

Android 14 (API level 34)

### Additional context

The warning appears when running `flutter run` on Android. Keeping `android.builtInKotlin=false` in gradle.properties as a temporary workaround.
P.s. created and work with DeepSeek

[HayesGordon]

Thanks for the report. Closing this as a duplicate of #648. PR to resolve this is in flight.