Merge "Decouple FUSE mount from main thread for demo user" into rvc-dev am: 931d7d2703 am: 4e14ca12d6 am: 0ee976f434

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12261202

Change-Id: If64e44d414585b3e331dcceadc359c5881309242