Merge "fs_mgr_overlayfs: Don't try to mount scratch if already mounted" into...

Merge "fs_mgr_overlayfs: Don't try to mount scratch if already mounted" into main am: 7bcd7715 am: 054526a6

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2797335



Change-Id: I30ea0fc92b93d5db39a3cc2a17f0b87457a358c6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>