Merge "Update drop target styling based for BC." into sc-dev am: f9f506ca7e am: bd8eec859f am: 73c5ef8416

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14332405

Change-Id: I64a3587f29c73110e16bf3cb1e8e4005eeb6a565