Minor change in Shared VPC LB sample
Minor change in Shared VPC LB sample

Update main.tf as per https://cloud.google.com/load-balancing/docs/proxy-only-subnets#proxy_only_subnet_create suggests recommendation

> For internal HTTP(S) load balancers, --purpose=REGIONAL_MANAGED_PROXY is the preferred setting even though --purpose=INTERNAL_HTTPS_LOAD_BALANCER also works.
terraform-google-modules/terraform-docs-samples,terraform-google-modules/terraform-docs-samples