Adjust Alertmanager alerts for parameter

Increase it to 3m to prevent flapping

Change-Id: I5ce143d3e8399d03f6f061d8e3b02ac53d7f0cfd
Prod-related: PROD-28183 (PROD:28183)
diff --git a/prometheus/meta/prometheus.yml b/prometheus/meta/prometheus.yml
index dcce961..b8266fd 100644
--- a/prometheus/meta/prometheus.yml
+++ b/prometheus/meta/prometheus.yml
@@ -61,7 +61,7 @@
     AlertmanagerNotificationFailureWarning:
       if: >-
         increase(alertmanager_notifications_failed_total[2m]) > 0
-      for: 2m
+      for: 3m
       labels:
         severity: warning
         service: alertmanager
@@ -71,7 +71,7 @@
     AlertmanagerAlertsInvalidWarning:
       if: >-
         increase(alertmanager_alerts_invalid_total[2m]) > 0
-      for: 2m
+      for: 3m
       labels:
         severity: warning
         service: alertmanager