[system:monitoring-agents] rename coredns metrics service (#1676)

## What this PR does
Renames coredns metrics service

### Release note
```release-note
Renamed coredns metrics service not to interfere with coredns service used for name resolution in tenant k8s clusters.
```

packages/system/monitoring-agents/templates/coredns-scrape.yaml

@@ -2,7 +2,7 @@
 apiVersion: v1
 kind: Service
 metadata:
-  name: coredns
+  name: coredns-metrics
   namespace: kube-system
   labels:
     app: coredns
@@ -19,7 +19,7 @@ spec:
 apiVersion: operator.victoriametrics.com/v1beta1
 kind: VMServiceScrape
 metadata:
-  name: coredns
+  name: coredns-metrics
   namespace: cozy-monitoring
 spec:
   selector: