Merge "DynamicSystemInstallationService: Support remount for DSU guest system" am: 4896c7f2ac am: b64a3f5871 am: ddff5bca30

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1537222

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib984c05213a1974fcdc59a59ed0ff47d260720a8