Ensure that `role.builtin` for cloned roles is always 0.

This is because `role.builtin` is being assigned a boolean value whereas the PG datatype is INTEGER.

https://github.com/theforeman/foreman/blob/develop/app/controllers/roles_controller.rb#L97

The attached bugzilla is not reproducable as upstream is fixed by commit: https://github.com/theforeman/foreman/blob/12612809c5deb885b13ceaf36b6a147c21688eb5/db/migrate/20160715131352_set_role_builtin_default.rb