Check user unlocked before write to /data/system_ce/0/snapshots am: 3ab9dc11

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17415776



Change-Id: I6d083a2930244ee65e5f17d2d61e1f9e0884d94e
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>