Wait for systemui udfps overlay ready to show settings udfps enroll view. am:...

Wait for systemui udfps overlay ready to show settings udfps enroll view. am: be823bc5 am: 93bcf812

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/23814463



Change-Id: I9fc884ce09f3858c53e7fe9fea2a664ac32f3e5c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>