Knative `knative-ingressgateway` is deprecated
Description
It appears that knative-ingressgateway is deprecated in favor of istio-ingressgateway.
Our Knative charts actually deploy both services at the moment but knative-ingressgateway is deprecated in Knative 0.3 and is going to be removed in Knative 0.4
We should update our code to present istio-ingressgateway external IP address in the UI, instead of knative-ingressgateway