Merge "Enable dimming for mid-range luminance wallpapeprs." into sc-dev am: 4bb78410 am: 391d414b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14881020

Change-Id: Ia18cfe8f38c93281b725dbda7f1769817a0d3c1e