services.billing.v1alpha3.UpdateBillingPlanRequest(UpdateBillingPlanRequest)

{
    "billing_plan_id": "string",
    "billing_plan": {
        "billing_plan_id": "string",
        "title": "string",
        "type": "BILLING_PLAN_TYPE_UNSPECIFIED",
        "is_draft": true,
        "start_time": "1s",
        "create_time": "1s",
        "update_time": "1s",
        "delete_time": "1s",
        "user_id": "string"
    },
    "update_mask": "string"
}