Merge "remount: prefer 'cache' backing storage for non-A/B devices" am: 955460e5

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2276426



Change-Id: Ie8ff40549f66235f1a76486e6867e75400d6f49a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>