Status.plist-- its entire job is to track
the status of that backup.
So when we look at this, we see IsFullBackup, the version,
the unique ID of that device, the date/time stamp.
It always says BackupState new; I'm not sure why.
BackupState finished-- that's really what we're looking for.
We want to see that it's finished.
And what we could say is on 3/30/2018 at 19:51:05 UTC,
the user created a backup.
It's only job is to track the backup,
but it only works if it was successful.