vpc
The network scope of the backends that can be added to the backend service. This field can be either GLOBAL_VPC_NETWORK or REGIONAL_VPC_NETWORK. A backend service with the VPC scope set to GLOBAL_VPC_NETWORK is only allowed to have backends in global VPC networks. When the VPC scope is set to REGIONAL_VPC_NETWORK the backend service is only allowed to have backends in regional networks in the same scope as the backend service. Note: if not specified then GLOBAL_VPC_NETWORK will be used.