Cover with a test that extraLabelsForMetrics are honoured

tests/prometheus/prometheus.yaml

@@ -38,6 +38,18 @@ tests:
       - equal:
           path: spec.externalLabels.k8s_cluster_name
           value: test
+  - it: extra labels for metrics are honoured
+    set:
+      kubernetes.clusterName: test
+      metrics.prometheus.server.extraLabelsForMetrics:
+        test: bar
+    asserts:
+      - equal:
+          path: spec.externalLabels.k8s_cluster_name
+          value: test
+      - equal:
+          path: spec.externalLabels.test
+          value: bar
   - it: should be deployed with no remoteWrites if no fluentbit is available
     set:
       kubernetes.clusterName: test