Some restore passes bring an ancestral dataset to the application, but
others instead act to bring an app back into sync with its own most-
recently-saved data. In the latter case the state file written by the
app after the restore is a correct basis for generating future backup
deltas, but in the former case it is not.
The app should not be required to distinguish between these cases;
the framework has all the information necessary to handle the saved
state correctly following any flavor of restore operation. This
patch makes the Backup Manager properly cause a full backup pass
following an ancestral-dataset restore. After a current-set
restore the saved state file is an accurate description for
purposes of continued backup operations, so is preserved.
(Cherrypick from master to gingerbread)
Change-Id: I4bc4e8782a168ecc0795107a340bdbb35060730e
bbff7ed44b