[RHOCP 4] Private OpenShift clusters should by default provision private LoadBalancers

Issue

When installing a private OpenShift cluster, the assumption is that nothing is exposed to the internet. By private, it means that the OpenShift cluster can only be accessed from an internal network and that cluster is not visible and reachable from the internet. When creating a service of type LoadBalancer for a private OpenShift cluster provisioned on AWS, it creates a public LoadBalancer and is assigned a public IP address, exposing a private cluster to the internet and causing unwanted security breaches.