In Liberty, we sent a warning if service_name was not set (and auth_name
was configured as the service name), with the goal to define the correct
default value during Mitaka.
This patch set the service_name parameter to 'Volume Service' by default
to match with Keystone's default catalog. Note: if you already run
OpenStack, when you'll run Puppet after this change, the old service
will still be present and you'll have to drop it manually. Though the
Cinder endpoint will be updated with the new service.
Change-Id: I3bfed1b91f99f4da5ba19d2b1f847346fa19beec
Closes-bug: #1506061
9125857f42