Merge "Headless: fix system update notification" into udc-dev am: 26633c8c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22741446



Change-Id: Ic7d4c7e5d2c1ae303b967ab070873e93a24412c1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>