Merge "Add a background scrim to launcher for text protection." into sc-dev am: f1d3cf02c9 am: dde42b46ab am: 353a880fe9

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14243130

Change-Id: Ib1ce99119dc6e337f37badbf9326f11b5699aa22