Update template's custom field responses.

{
  "customFieldResponses": [
    {
      "customFieldId": "f49d00fe-1eda-4304-ba79-a980f565281d",
      "responseItems": [
        {
          "response": "Leisure travel",
          "additionalInput": "20"
        }
      ],
      "travelerAccess": "HIDDEN"
    }
  ],
  "customFieldV3Responses": [
    {
      "readOnly": true,
      "hidden": true,
      "selectedOptions": [
        {
          "additionalInfoConfigs": [
            {
              "type": "VARIABLE",
              "name": "LLF"
            }
          ]
        }
      ]
    }
  ]
}