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

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



Change-Id: Iaf03d41e53a8718c177d02490b5a6ef29e4f8a33
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>