Merge "Dim wallpaper by setting wallpaper layer transparency." into sc-dev am:...

Merge "Dim wallpaper by setting wallpaper layer transparency." into sc-dev am: 76fda9db am: c79c20c8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14486205

Change-Id: Id29c2466effab17cc59e9c373d0f5a36bf797bfb