Parametrize mcp_docker_registry host

Related-Bug: PROD-22480 (PROD:22480)

Change-Id: I36ad55a1960f6c8e025d9c967bbc7658927fc872
diff --git a/docker/swarm/stack/monitoring/alerta.yml b/docker/swarm/stack/monitoring/alerta.yml
index 5e99286..8c9d7aa 100644
--- a/docker/swarm/stack/monitoring/alerta.yml
+++ b/docker/swarm/stack/monitoring/alerta.yml
@@ -2,7 +2,8 @@
 - system.prometheus.alerta
 parameters:
   _param:
-    docker_image_alerta: docker-prod-local.artifactory.mirantis.com/mirantis/external/alerta-web:latest
+    mcp_docker_registry: 'docker-prod-local.artifactory.mirantis.com'
+    docker_image_alerta: ${_param:mcp_docker_registry}/mirantis/external/alerta-web:latest
     alerta_mongodb_uri: "mongodb://${_param:cluster_node01_address}:27017,${_param:cluster_node02_address}:27017,${_param:cluster_node03_address}:27017/alerta?replicaSet=stacklight"
     alerta_admin_username: "admin@alerta.io"
   docker:
diff --git a/docker/swarm/stack/monitoring/gainsight.yml b/docker/swarm/stack/monitoring/gainsight.yml
index 11344b7..5748034 100644
--- a/docker/swarm/stack/monitoring/gainsight.yml
+++ b/docker/swarm/stack/monitoring/gainsight.yml
@@ -2,6 +2,7 @@
 - system.prometheus.gainsight.container
 parameters:
   _param:
+    mcp_docker_registry: 'docker-prod-local.artifactory.mirantis.com'
     gainsight_enabled: 'true'
     gainsight_csv_upload_url: 'http://localhost:9999'
     gainsight_account_id: 'default'
@@ -14,7 +15,7 @@
     gainsight_config_directory: '/srv/gainsight'
     gainsight_crontab_directory: '/etc/cron.d'
     gainsight_config_path: "${_param:gainsight_config_directory}/config.ini"
-    docker_image_prometheus_gainsight: 'docker-prod-local.artifactory.mirantis.com/openstack-docker/gainsight:nightly'
+    docker_image_prometheus_gainsight: '${_param:mcp_docker_registry}/openstack-docker/gainsight:nightly'
   docker:
     client:
       stack: