Adds ability to override service names 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: I1d26aa7970471a40d7d636387826523925a71844
Merge "Adds ability to override service names for service catalog"