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

Merge "Defuse notification race around app stops" into tm-dev am: 81ac10a9 am: f7b82355 am: cc34a8a0 am: 46e262a2

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



Change-Id: Ie5fea4be8469fd441b7cffdde78aafb78940832a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>