Use 'openstack' in Grafana dashboard tags

Change-Id: I1a1190a5686ef533ed32e02f4d42210db50694a7
Related-Bug: PROD-17781
diff --git a/glance/files/grafana_dashboards/glance_prometheus.json b/glance/files/grafana_dashboards/glance_prometheus.json
index fe3ad38..0ff8930 100755
--- a/glance/files/grafana_dashboards/glance_prometheus.json
+++ b/glance/files/grafana_dashboards/glance_prometheus.json
@@ -1461,7 +1461,7 @@
   "sharedCrosshair": true,
   "style": "dark",
   "tags": [
-    "glance"
+    "openstack"
   ],
   "templating": {
     "list": [
diff --git a/glance/files/grafana_dashboards/glance_prometheus_fluentd.json b/glance/files/grafana_dashboards/glance_prometheus_fluentd.json
index b37cc23..c7ab77b 100755
--- a/glance/files/grafana_dashboards/glance_prometheus_fluentd.json
+++ b/glance/files/grafana_dashboards/glance_prometheus_fluentd.json
@@ -1461,7 +1461,7 @@
   "sharedCrosshair": true,
   "style": "dark",
   "tags": [
-    "glance"
+    "openstack"
   ],
   "templating": {
     "list": [