Merge "Enable split screen button in handle menu." into udc-qpr-dev am: 3bc34195 am: 0b8ab89f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23918397



Change-Id: I0f287fe4f0870134c584f9cb2b3048ad09325158
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>