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

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



Change-Id: I22f88b182f6a8a9a9cc62dd5ad6399c550225fcd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>