Merge "Fix volume slider not showing when casting in the background" into udc-dev am: f96e49ed

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23726250



Change-Id: Iee8417dd9edb92b2d37d63da49a10803e8e6b484
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>