Merge "fs_mgr_overlayfs: Fallback to allocate scratch on super if /data...

Merge "fs_mgr_overlayfs: Fallback to allocate scratch on super if /data failed" am: c0524606 am: 86d6d6da am: 31faa67c

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2269727



Change-Id: Iecaca0308184714419de7dfda82eb33314ae38bc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>