Merge "[aapt2] Add placeholder --feature-flags flag" into main am: 28226eec72 am: 1bad8c62e2 am: f6c4693ec2

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2806055

Change-Id: Ibcd3039a8912cbc68e0ec8cf1f1f6f99f36304e5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>