When uninstalling SN Platform, Grafana PVC remains

[zbentley]

If I do helm install of an SN-platform instance use that instance for awhile, and then helm uninstall it, everything is cleaned up except for one PersistentVolumeClaim and its associated volumes: the one used for Grafana.

Given an installation name of pulsar-blt, after uninstallation completes I still have a PVC named pulsar-blt-sn-platform-grafana-data-pulsar-blt-sn-platform-grafana-0.