Fix delete istio-operator namespace error (#18497)
Fix delete istio-operator namespace error (#18497)

* Fix delete istio-operator namespace error

* Check whether ns is deleted

smawson/istio,smawson/istio,smawson/istio,istio/istio,istio/istio,smawson/istio,smawson/istio,smawson/istio,istio/istio,istio/istio,istio/istio