DataValidationRule

{
    "condition": {
        "type": "CONDITION_TYPE_UNSPECIFIED",
        "values": [
            {
                "relativeDate": "RELATIVE_DATE_UNSPECIFIED",
                "userEnteredValue": "string"
            }
        ]
    },
    "inputMessage": "string",
    "showCustomUi": true,
    "strict": true
}