Added config file for alertad.

Fixes PROD-35069

Change-Id: Id001d2473a350acc5ab3baa8c8630ed0c275c456
diff --git a/prometheus/alerta/init.yml b/prometheus/alerta/init.yml
index a82e8d4..6e16b63 100644
--- a/prometheus/alerta/init.yml
+++ b/prometheus/alerta/init.yml
@@ -1,2 +1,7 @@
 classes:
   - service.prometheus.alerta
+parameters:
+  prometheus:
+    alerta:
+      timeouts:
+        alert: 28800