fix(alerts): expand nightly downtime window (#248)

Author: afeld

terraform/suppress.arm.json

@@ -26,7 +26,7 @@
             {
               "recurrenceType": "Daily",
               "startTime": "06:00:00",
-              "endTime": "06:10:00"
+              "endTime": "06:20:00"
             }
           ]
         },