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

Merge "Set preference background color as transparent" into udc-dev am: 706cc584 am: feaf6682 am: dbb2437a

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



Change-Id: I780c884702eeeffb947e373911a32731abd5974c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>