Adds ability to override service name for service catalog

Instead of forcing the name of the service in the service catalog to
match auth_name, this allows the ability to explicitly set the service
name, spearately from auth_name.
If service_name is not specified, it's value defaults to the value
of auth_name (which maintains the current behavior.)

Closes-bug: #1359755
Change-Id: I66dadaebb526cfae2b6c250b2bef97e1e6d6aafe
Merge "Adds ability to override service name for service catalog"