Fix Barbican client (Castellan) with TLS (part 2)

This patch is a continuation of
I6a174468bd91d214c08477b93c88032a45c137be for the nova-cell role, which
was missed.

The Castellan (Barbican client) has different parameters to control
the used CA file.
This patch uses them.
Moreover, this aligns Barbican with other services by defaulting
its client config to the internal endpoint.

See also [1].

[1] https://bugs.launchpad.net/castellan/+bug/1876102

Closes-Bug: #1886615

Change-Id: I056f3eebcf87bcbaaf89fdd0dc1f46d143db7785

ansible/roles/nova-cell/templates/nova.conf.j2

@@ -222,7 +222,8 @@ connection_string = {{ osprofiler_backend_connection_string }}
 {% if enable_barbican | bool %}
 [barbican]
 auth_endpoint = {{ keystone_internal_url }}
-cafile = {{ openstack_cacert }}
+barbican_endpoint_type = internal
+verify_ssl_path = {{ openstack_cacert }}
 {% endif %}
 
 # Cell specific settings from DevStack: