Deprecated Gradle features were used in this build, making it incompatible with Gradle 6

Have you tried running ./gradlew bundleRelease --warning-mode all?

It will give you more info on what are incompatible.

This happened to me in a React Native project. This is the step-by-step to fix it in Windows (10 64bits):

1) Run avd without Android Studio (https://windowsloop.com/launch-avd-manager-without-android-studio/)

2) In another console run in your project gradle wrapper (you must to have installed Gradle 5.4.1 (https://gradle.org/install/))

3) Then move to cd android, here run gradlew clean

4) Move to root cd.. and run react-native start

5) In another console run in your project react-native run-android