Add keycloak auth config to Zuul

This adds a keycloak realm to the Zuul auth config, so that we can
log into the zuul web ui with our test realm in keycloak.

Change-Id: Iec3777a6ea1cba0e108c7e44067d69b61cbb34a7

playbooks/roles/zuul/templates/zuul.conf.j2

@@ -77,6 +77,13 @@ client_id=zuul.opendev.org
 issuer_id=zuul.opendev.org
 secret={{ zuul_local_auth_secret }}
 
+[auth keycloak]
+default=true
+driver=OpenIDConnect
+realm=zuul
+issuer_id=https://keycloak.opendev.org/auth/realms/zuul
+client_id=zuul
+
 {% for connection in zuul_connections -%}
 [connection "{{ connection['name'] }}"]
 {% for key, value in connection.items() -%}