Enable Neutron server health check

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

Change-Id: I9f919e9e486c0557fa261d58891cb5c3ce250acd
Depends-On: I290704c72e104e40d104d63583155d0eba7c128e

docker/services/neutron-api.yaml

@@ -148,6 +148,8 @@ outputs:
                 net: host
                 privileged: false
                 restart: always
+                healthcheck:
+                  test: /openstack/healthcheck
                 volumes:
                   list_concat:
                     - {get_attr: [ContainersCommon, volumes]}