Is there sample source code available or guideline published by Firebase on same? Looking for sample code in java which follows best practices specific to firebase in android mobile app
Google Play’s app account deletion requirements - https://support.google.com/googleplay/android-developer/answer/13327111
If you just want to delete the user account from Firebase Authentication, you can call this API.
If you want to delete auxiliary data from specific other products, you can use this extension: Delete User Data.
If you need to delete data from other sources too, you will have to write your own application code for that. You can of course file a feature request for Firebase or the extension to add such functionality, but given the multitude of systems where such data could be stored, it is unlikely that will happen - and even less likely it'd happen in a timeframe that matches your needs.