Fix Ceph OSD Overview dashboard

Change from TS mode to Histogram

Change-Id: If491fac4c25607bce7b9cb34289aee1b2a14b4a3
Related-PROD: PROD-31454
diff --git a/ceph/files/grafana_dashboards/osds-overview_prometheus.json b/ceph/files/grafana_dashboards/osds-overview_prometheus.json
index 49c1cb5..3337014 100644
--- a/ceph/files/grafana_dashboards/osds-overview_prometheus.json
+++ b/ceph/files/grafana_dashboards/osds-overview_prometheus.json
@@ -383,7 +383,7 @@
     },
     {
       "aliasColors": {},
-      "bars": false,
+      "bars": true,
       "dashLength": 10,
       "dashes": false,
       "datasource": null,
@@ -405,11 +405,11 @@
         "max": false,
         "min": false,
         "rightSide": false,
-        "show": true,
+        "show": false,
         "total": false,
         "values": false
       },
-      "lines": true,
+      "lines": false,
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
@@ -427,7 +427,7 @@
         {
           "expr": "ceph_osd_numpg",
           "format": "time_series",
-          "instant": false,
+          "instant": true,
           "intervalFactor": 1,
           "legendFormat": "PGs per OSD",
           "refId": "A"
@@ -446,7 +446,7 @@
       "type": "graph",
       "xaxis": {
         "buckets": 20,
-        "mode": "time",
+        "mode": "histogram",
         "name": null,
         "show": true,
         "values": []