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

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



Change-Id: I663c2a4523d2ba3c91c7b77d9544be3113d49fec
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>