Create single dialog for adding a user. am: 709264ad am: e1c6abe8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22849716



Change-Id: I2af1b88f7dbb0501740070448183631c05298857
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>