Merge "Show system notifications when DnD is enabled" into tm-dev am: ab13fd85 am: eb449d2c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18752505



Change-Id: Idbd2b4abcedc9d2e4500634426128bfcb240f237
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>