Merge "Change unfold background color based on split screen state" into udc-dev am: 550f35fc am: 0cb35c55 am: b3ee24c1 am: 41f2a806

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23083218



Change-Id: Idff4ef5d1ab141beab9e93fbfe58df35bcdc8940
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>