In the past, this was done when installing/upgrading full istio, and involved some duplication - ports configured
both in upgrade, Gateway and VirtualService.

The new Ingress chart uses a 'values.yaml' (see user-example-ingress), which auto-generates Service ports,
Gateways and basic VirtualService. It is still possible to only configure the ports in Service, and do manual
config for the rest.

-- easier reconfig of just the gateway
-- TLS secrets and domain name management is isolated, for better security
-- simplified configuration
-- multiple versions of the ingress can be used, to minize upgrade risks

- the new chart uses the default namespace service account, and doesn't require
additional RBAC permissions.

- simplified label structure. Label change is not supported on upgrade.