Add support for android_library modules

Add support for compiling android_library modules into AARs,
and refactor app support on top of it.

Bug: 73724997
Test: app_test.go
Change-Id: I1dfac5fffe577c6680bc4709147b2061eb7d819c
Merged-In: I1dfac5fffe577c6680bc4709147b2061eb7d819c
(cherry picked from commit a97c5d3f)