Move few docker_images* under 'defaults' logic

   * Move all docker-images-artifacts under one class
   * This patch affect only:
     - docker-images CI\CD

Change-Id: I534c3a1d642bfb522e4ae8f195906de8f9ee718e
diff --git a/docker/swarm/stack/janitor_monkey.yml b/docker/swarm/stack/janitor_monkey.yml
index fb926e8..0cb8c43 100644
--- a/docker/swarm/stack/janitor_monkey.yml
+++ b/docker/swarm/stack/janitor_monkey.yml
@@ -1,7 +1,6 @@
 parameters:
   _param:
     docker_janitor_monkey_replicas: 1
-    docker_image_mongodb: library/mongo:3.4
     docker_mongodb_admin_username: admin
     docker_mongodb_admin_password: password
     docker_image_janitor_monkey: ${_param:mcp_docker_registry}/mirantis/oss/janitor-monkey
@@ -71,7 +70,7 @@
             simianarmy.janitor.notification.oss.application_id: ${_param:janitor_monkey_notification_oss_application_id}
           service:
             cleanup-service-mongodb:
-              image: ${_param:docker_image_mongodb}
+              image: library/mongo:3.4
               deploy:
                 replicas: ${_param:docker_janitor_monkey_replicas}
                 restart_policy: