All the required configuration to deploy Azure gateways will be absorbed
as a part of request body in this API and gateway deployment will be
triggered. Deployment progress can be known from GetAzureGatewayStatus API.
Upon successful deployment of a gateway, the deployment_step will be
DEPLOYMENT_SUCCESSFUL gateway_status will be UP and op_status of the VNET
will be NSX_MANAGED_BY_GATEWAY. If any error is encountered during
deployment, corresponding error_code and error_message will be populated
in gateway_instances_status. To manage a compute VNET using transit VNET,
user needs to undeploy gateway and onboard the compute VNET
using /csm/azure/vnets/?action=onboard API.