The current obb support was specific to the Google Play store which has deprecated the format in favor on Android bundle and Play asset delivery.
For projects that still have a dependency on the Play store obb support, the deprecated logic has been moved into a separate Godot Obb Android plugin.
Both the `app` and `lib` modules had custom source sets configuration originating from the early days of the project. This updates the configuration to match the default Android Studio configuration which will simplify the addition of unit tests and instrumented tests to the project.
Note that for backcompat reasons, some folders (such as the `res` folder in the `app` module) are left as is.