Merge "Use a selector instead of loading resource for drop target." into sc-dev am: b1e51e2a3f am: 4d296cc3d8 am: 7fa2c6c265

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14817811

Change-Id: I5d79a13ed4a2104d94e0d0093bce7cad6900b7bf