Merge "[aapt2] Add placeholder --feature-flags flag" into main am: 28226eec...

Merge "[aapt2] Add placeholder --feature-flags flag" into main am: 28226eec am: ea23cb3b am: bc876a99

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



Change-Id: I5bbd7af31f6b92789a05d181fc55792c2c1aa579
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>