Merge "Make DragAndDropController optional" into udc-dev am: 2d094275 am: b3423ad6 am: 67ffea0a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22837777



Change-Id: If28042799e8cf036b2c0b8a4b16a869439540eab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>