Merge "Prepare user storage when a private volume has been mounted." into...

Merge "Prepare user storage when a private volume has been mounted." into rvc-dev am: 9df5ebf7 am: dd53a609

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11367150

Change-Id: I26ed2ed92e52d2ebd0acf42ab8484b2aefe56776