Merge "Move WallpaperColorHints RPC calls to a background thread." into udc-qpr-dev am: 0487d8ee9b am: 28c69acdfe

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/24087102

Change-Id: I66833830e2e20dcb23ed9abd80b72bec8cefe378
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>