Merge "Set preference background color as transparent" into udc-dev am:...

Merge "Set preference background color as transparent" into udc-dev am: 706cc584 am: 96f940bd am: b738ef70

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23008277



Change-Id: I820de91a890be747e71049c41305bd0950159975
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>