CoEnrollmentAttributeDefault function validateModifiable assumes Router object

We are creating a CoJobBackend class that creates enrollment flows, attributes, and defaults.  validateModifiable function of CoEnrollmentAttributeDefault assumes it can use the Router to get the request info. The request object is only available when used via the MVC framework, not when invoked in a cron job or other script. 

The result is a warning is generated " Warning: Attempt to read property "data" on null in [/srv/comanage-registry/app/Model/CoEnrollmentAttributeDefault.php, line 92]" and the verification is not performed. 

I think this was introduced in commit  5b12333. See https://github.com/Internet2/comanage-registry/commit/5b12333f644c372f63f23af5fef5cf5a844e715d.