Merge "libsnapshot:snapuserd: Transitions for snapuserd" am: e19df50b75 am: 47014a7514 am: 1858f39d97 am: 9f3c518ed9

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

Change-Id: Ia878c9dd6bcf9235587aaa53fa1dfcbefe3c7452