Merge "Make unregister receiver "sync"." into tm-dev am: 8af79601

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17663485



Change-Id: I3b3cf230c561759fe6e50bd2989a31e7a1e33b28
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>