Revert "Add monitoring for cron job"

As we resign to develop full-stack solution to monitor cron jobs

This reverts commit 697ce4bf04b79bcac7d37845ba8c17fe34a76f2e.

Change-Id: Icab6008011141bb658c836897a05018dd6ce2984
diff --git a/linux/meta/prometheus.yml b/linux/meta/prometheus.yml
index 99cb54c..ca4ba3d 100644
--- a/linux/meta/prometheus.yml
+++ b/linux/meta/prometheus.yml
@@ -188,15 +188,6 @@
       annotations:
         summary: "Cron process is down"
         description: "The cron process on the {{ $labels.host }} node is down."
-    CronJobFailure:
-      if: >-
-        min(cron_job_status) by (name, host) == 0
-      labels:
-        severity: major
-        service: system
-      annotations:
-        summary: "Cron job failure"
-        description: "The {{ $labels.name }} cron job on the {{ $labels.host }} node failed."
     SshdProcessDown:
       if: >-
         procstat_running{process_name="sshd"} == 0