This reverts commit 920639511d.
The changes are good, this revert is only done for release management reasons
as we want this feature to get more testing before making it in a stable build,
but a 3.2.3 release is imminent to handle some regressions in 3.2.2.
This will be re-committed in a 3.2-based feature branch, and we'll merge it
again once we're confident about it (probably for 3.2.4).
The application module `app` serves double duties of providing the prebuilt Godot binaries ('android_debug.apk', 'android_release.apk') and the Godot custom build template ('android_source.zip').