Update Service Agreement permissions
Fix updating an Service Agreement so that depositors email address can be changed. Changing email address also chnages view and edit permissions of the Service Agreement.
This fixes the Null Pointer Exception that was happening when attempting to retrieve MetadataInfo from the ServiceAgreement object that came in from the request. Instead MetadataInfo needs to be retrieved from file, updated, then saved back to file.
What this doesn't address is that the original depositor email address will still have permission to view and edit the Service Agreement. Will leave this for a future decision.