Make sure octavia uses internal endpoint to barbican

The octavia service communicates to the barbican service with
public endpoint_type by default[1], it should use internal
like other services.

[1] 0056b5175f/octavia/common/config.py (L533-L537)

Closes-Bug: #1875618
Change-Id: I90d2b0aeac090a3e2366341e260232fc1f0d6492

ansible/roles/octavia/templates/octavia.conf.j2

@@ -15,6 +15,8 @@ ca_private_key = /etc/octavia/certs/private/cakey.pem
 ca_certificate = /etc/octavia/certs/ca_01.pem
 {% if enable_barbican | bool %}
 region_name = {{ openstack_region_name }}
+endpoint_type = internal
+ca_certificates_file = {{ openstack_cacert }}
 {% endif %}
 
 [haproxy_amphora]

releasenotes/notes/use-internal-endpoint-for-barbican-in-octavia-0bcdcf91a8adc95c.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Switch endpoint_type from public to internal for octavia
+    communicating with the barbican service. See
+    `bug 1875618 <https://bugs.launchpad.net/kolla-ansible/+bug/1875618>`__
+    for details.