Merge changes from topic "unencrypted-dirs-r" into rvc-dev

* changes:
  [RESTRICT AUTOMERGE] Log to EventLog on prepareUserStorage failure
  [RESTRICT AUTOMERGE] Ignore errors preparing user storage for existing users
  [RESTRICT AUTOMERGE] UserDataPreparer: reboot to recovery for system user only
  [RESTRICT AUTOMERGE] UserDataPreparer: reboot to recovery if preparing user storage fails
  [RESTRICT AUTOMERGE] StorageManagerService: don't ignore failures to prepare user storage