Merge "Bring fullscreen backdrop frame back" into tm-dev am: 957b746c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17469883



Change-Id: Iad85756b885c420c874eda34f265f3d0044bccae
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>