Merge "Update drop target styling based for BC." into sc-dev am: f9f506ca7e am: 7182197500 am: 4685b86de2

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

Change-Id: I9bc1761ad9200806b337c7db5597c4950a590b2c