All the required configuration to deploy AWS 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 GetAwsGatewayStatus API.
Upon successful deployment of a gateway, the deployment_step will be
DEPLOYMENT_SUCCESSFUL gateway_status will be UP and op_status of the VPC
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 VPC using transit VPC,
user needs to undeploy gateway and onboard the compute VPC
using /csm/aws/vpcs/?action=onboard API.