Merge "Update taskbar background color." into tm-qpr-dev am: 906ad8b853 am: 903ff4c926

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/22211883

Change-Id: If2248c206b1d9a17c9f25af46bcdb48f2d224db8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>