Merge "Remove volume_separate_notification flag" into udc-dev am: 485a8116 am: 53eb878f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23221865



Change-Id: If2ba79dbb8855160b6f559cad6759374c37071a2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>