IstioD is using too many resources when lots of pods are being added/churned

[RobertLucian]

Description

Find a way to disable the monitoring of k8s resources so that istiod stops using so many resources.

Consequence

When istiod uses too much memory, it triggers an OOM event on the other pods collocated on the same instance such as the ingress gateways, the cluster autoscaler, the operator, etc. Or it can make k8s evict the other pods which is equally bad. This can render the cluster unusable.