Enable octavia-api health check

This patch enables health check execution for octavia-api docker container.

Change-Id: Ideadef40d88c7042dc75523c8c9e2889979992de
Depends-On: Ie8eaab9919bde61793a3310328ee9f117c4e58da
Depends-On: Id5dc7d169301e45cb0abab7cecae67457db9fd96

docker/services/octavia-api.yaml

@@ -138,6 +138,8 @@ outputs:
                 net: host
                 privileged: false
                 restart: always
+                healthcheck:
+                  test: /openstack/healthcheck
                 volumes:
                   list_concat:
                     - {get_attr: [ContainersCommon, volumes]}