Merge "libsnapshot:snapuserd: Transitions for snapuserd" am: e19df50b75 am: 47014a7514 am: 1858f39d97

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1437277

Change-Id: I1d462a2ec3bdde11d261caf73526020392cf1f4f