Add API availability alert for Prometheus

Change-Id: Ica5b15863e550d68e9653248c80c3a6c7a3865a4
diff --git a/metadata/service/support.yml b/metadata/service/support.yml
index 5ceec61..d1f3754 100644
--- a/metadata/service/support.yml
+++ b/metadata/service/support.yml
@@ -13,3 +13,5 @@
         enabled: true
       grafana:
         enabled: true
+      prometheus:
+        enabled: true
\ No newline at end of file