Enable nova placement health check

This patch enables health check execution for Nova placement API
docker container.

Change-Id: I8c53308e07e1487eecb90f3c35864ea77a3c2937
Depends-On: Ib82cb849540694106a869ec81694f1159967ee79

docker/services/nova-placement.yaml

@@ -115,6 +115,8 @@ outputs:
             net: host
             user: root
             restart: always
+            healthcheck:
+              test: /openstack/healthcheck
             volumes:
               list_concat:
                 - {get_attr: [ContainersCommon, volumes]}
@@ -171,4 +173,3 @@ outputs:
           when:
             - step|int == 2
             - remove_httpd_package|bool
-