Merge "Fade out empty Overview message." into sc-dev am: 13e4618b57 am: 140af43f10 am: acc73ebdb3

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14415793

Change-Id: I0e45cdbcc43f577f710aec71a48eba9b6c6d8d0a