Terraform Script for Istio Gateway Missing "aks_dns_host" in Terraform Variable Configuration

In Service Resource deployment step, terraform variable "aks_dns_host" needs to be allowed to be customized to match the actual DNS A record. It is missing in the default "infra\templates\osdu-r3-mvp\service_resources\terraform.tfvars" file and missing in the wiki customization script for "custom.tfvars" file. This leads to the wrong Host name (default contoso.com) being added to the Backend setting in the istio gateway deployed by the istio Helm Chart in later stage.