Remove Crunchy Grafana and Crunchy Prometheus References
Remove Crunchy Grafana and Crunchy Prometheus References

This update removes references to the Crunchy Grafana and
Crunchy Prometheus containers from pre-pull-crunchy-containers.sh.
These containers have been replaced by the upstream Grafana and
Prometheus containers.

CrunchyData/postgres-operator,CrunchyData/postgres-operator