Extend procstat_running-based metric alerts.

Related-PROD: PROD-35435
Change-Id: I55507bb19da4f7844970e2d139790527fdd88fe0
diff --git a/salt/meta/prometheus.yml b/salt/meta/prometheus.yml
index 1a2a5a7..c38e2f2 100644
--- a/salt/meta/prometheus.yml
+++ b/salt/meta/prometheus.yml
@@ -7,6 +7,7 @@
     SaltMasterServiceDown:
       if: >-
         procstat_running{process_name="salt-master"} == 0
+      for: 2m
       labels:
         severity: critical
         service: salt
@@ -20,6 +21,7 @@
     SaltMinionServiceDown:
       if: >-
         procstat_running{process_name="salt-minion"} == 0
+      for: 2m
       labels:
         severity: critical
         service: salt