Merge "Send error if enroll is invoked when face is already enrolled" into udc-dev am: 78ae4649

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22651490



Change-Id: Ia27736771b34b82370169c8767c6b2108b6cf8a0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>