Merge "Make flushing broadcast loopers optional." into udc-dev am: 3e7d7d63 am: def3c2f6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23224746



Change-Id: I9343b562ee066f58a58581ae62113124871f02be
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>