removed secret dumps and deprecated --export from dump_kubernetes.sh (#25361)
removed secret dumps and deprecated --export from dump_kubernetes.sh (#25361)

* removed secret dumps and deprecated --export from dump_kubernetes.sh


added cmd option to dump secrets


typo

* use doublequotes around vars
istio/istio,istio/istio,istio/istio,istio/istio,istio/istio