Grafana dashboards are attempted to be created before managed grafana instance is available

In the `./build/k8s/bundle.sh` script, it will optionally allow you to create a managed grafana instance. While it did wait for the creation to be completed, the grafana instance was not available yet, so when it attempted to create the dashboards, it failed. We either need to wait for grafana instance to be fully available or perhaps add retries around the dashboard creations.