Add Alertmanager prometheus endpoint and replace ports with variables

Change-Id: I55867b8e483e48204d6393a3542f254556262905
diff --git a/docker/swarm/service/monitoring/prometheus_alertmanager.yml b/docker/swarm/service/monitoring/prometheus_alertmanager.yml
index 5d5f237..942fa42 100644
--- a/docker/swarm/service/monitoring/prometheus_alertmanager.yml
+++ b/docker/swarm/service/monitoring/prometheus_alertmanager.yml
@@ -1,4 +1,4 @@
-include:
+classes:
 - service.prometheus.alertmanager.container
 parameters:
   docker: