Support merging AARs

[Goooler]

Hey there! It seems out of the box that the ShadowJar task only operates on Java Artifacts (JARs). I wanted to link to this repo, which serves as an example Gradle Plugin that allows you to use the ShadowJar task for Android libraries, which are Android Artifacts (AARs). Hopefully this helps!

Originally posted by @devinmorgan in #498

[Goooler]

Also addresses

• Unable to create android AAR #144
• Possible to use shadowJar with com.android.library modules? #183
• Android: Renaming the Package of a Dependency #209
• Relocating not working - Android project #498
• Could not find method shadowJar() for arguments .. on project ':app' of type org.gradle.api.Project. #889

[Goooler]

May https://developer.android.com/build/publish-library/fused-library?