Merge "Enable referencing of aapt-generated proguard flags" am: 7fecde90 am: dd1a7fff

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2516696



Change-Id: Id46451a67c81496119d193efe626d4164628074a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>