Update Current Leader query (#12465)

metrics/scripts/grafana-provisioning/dashboards/cluster-monitor.json

@@ -136,7 +136,7 @@
           "hide": false,
           "orderByTime": "ASC",
           "policy": "default",
-          "query": "SELECT MODE(last) FROM ( SELECT last(\"leader\") FROM \"$testnet\".\"autogen\".\"replay_stage-new_leader\" WHERE $timeFilter GROUP BY host_id )\n",
+          "query": "SELECT last(\"leader\") FROM \"$testnet\".\"autogen\".\"replay_stage-new_leader\" WHERE $timeFilter ORDER BY \"time\" desc \n",
           "rawQuery": true,
           "refId": "A",
           "resultFormat": "table",
@@ -12786,4 +12786,4 @@
   "title": "Cluster Telemetry",
   "uid": "monitor",
   "version": 1
-}
+}