Flutter Android SDK Compatibility Fix

Description:
I have a Flutter project targeting Android with minSdkVersion set to 16, but the build currently fails due to plugin and Gradle/JDK configuration issues. I need an Android/Flutter expert to adjust the project so that:

The Android module builds successfully with minSdkVersion 16

All plugins (e.g. google_mobile_ads, webview_flutter) are configured or downgraded to versions compatible with API 16+

Gradle Wrapper, Android Gradle Plugin, and JDK settings are harmonized to eliminate “Unsupported class file major version 65” and other Java/Gradle errors

flutter build appbundle --release completes without errors

The resulting AAB supports Android devices from API 16 onward

ProGuard / R8 deobfuscation mapping is correctly generated/uploadable (optional bonus)

Deliverables:

Updated android/build.gradle, gradle-wrapper.properties, and android/gradle.properties files

Any necessary changes to pubspec.yaml (plugin version adjustments)

A clean, repeatable build script or instructions (flutter clean + flutter build appbundle --release)

Confirmation that the AAB installs and runs on an emulator or device with API 16

Git commit(s) with clear messages

Requirements:

Proven experience with Flutter Android builds and Gradle configuration

Strong knowledge of Android SDK versions, Gradle Wrapper, and JDK compatibility

Familiarity with common Flutter plugins and their Android requirements

Ability to work remotely, communicate clearly in English, and deliver within agreed timeframe

Please include in your proposal:

Brief summary of your relevant experience

Approach you’ll take to solve the SDK/Gradle/JDK compatibility issues

Estimated timeline and budget

Looking forward to working with you!