Merge "Defuse notification race around app stops" into tm-dev am: 81ac10a9 am: 07d303a1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18624638



Change-Id: Ic2bc4ad19896795c1b5b3ea53478a080325a999d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>