services.billing.v1alpha1.UpdateDefaultBillingPlanRequest(UpdateDefaultBillingPlanRequest)

{
    "billing_plan_id": "string",
    "billing_plan": {
        "billing_plan_id": "string",
        "create_time": "1s",
        "update_time": "1s",
        "start_time": "1s",
        "end_time": "1s",
        "delete_time": "1s",
        "rate_definition_ids": [
            "string"
        ],
        "status": "BILLING_PLAN_STATUS_UNSPECIFIED",
        "actual_start_time": "1s"
    },
    "update_fields": "string"
}