Merge "Return error in "sm unmount-app-data-dirs" if app data isolation is not enabled" am: 4d53e3b9bc

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1556237

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: If03f03feb9f89a15fa5ca0e6145fbe87a5a150a1