This updates the grafana dashboards to use a default refresh
value of 5m to prevent dashboards with intensive queries (like the
container dashboard) from submitting frequent, expensive requests
to Prometheus
This also removes the override to disable the ingress service for
grafana in the developer deployment script, as it was overlooked
when enabling ingresses after the ingress chart was introduced
Change-Id: I0958a3978cec25a1350172cbe75996f1346858c5
9ee7561521