Describe kube-state-metrics to check labels

For bring-your-own KSM installations, it would be great if kube-diag included a `kubectl` describe of the `kube-state-metrics` pod.

This would allow comparing the labels on the kube-state-metrics pod with the default scrape labels.

More: https://github.com/newrelic/helm-charts/blob/master/charts/nri-bundle/README.md#bring-your-own-ksm