Fix bugs and improve monitoring support.

Fixed test setup issue and missing cleanup of monitoring firewall rules.
Added logic to generate an unique password for Grafana as part of Cluster bring up
Modified the pod description to always use the 'latest' image to avoid pulling all the tags, thereby reduce startup latency.
cc @lavalamp 
Indentation is weird. 4 spaces initially and then 3 spaces next?

Most of the rest of the shell scripts seem to use 2 space indentation consistently, I think it would be better to stick to that.

(I see that the other "setup-monitoring" function has indentation problems, but that means that one should be fixed [in a separate commit] and not this one broken to match that one.)