Do not fail for old Kubernetes versions on ingressclass (#22754)
Do not fail for old Kubernetes versions on ingressclass (#22754)

This was added on k8s 1.18, so most users do not have support and will
get error log spam. Instead, check at startup if we support it, and
otherwise ignore
smawson/istio,smawson/istio,istio/istio,istio/istio,istio/istio,istio/istio,smawson/istio,smawson/istio,smawson/istio,istio/istio,smawson/istio