Merge "Conform the logic to decide wallpaper darkness" into udc-dev am:...

Merge "Conform the logic to decide wallpaper darkness" into udc-dev am: 223a0a22 am: ef65b63e am: fbbc5593 am: 16e9ace8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23617998



Change-Id: I66a63b81cc4b4554263bb9aaa8585e1c446c3d72
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>