A contract for attorney’s fees for services in litigation, made by or on behalf of a minor, is void unless the contract is approved, on petition by an interested person, by the court in which the litigation is pending or by the court having jurisdiction of the guardianship estate of the minor. If the contract is not approved and a judgment is recovered by or on behalf of the minor, the attorney’s fees chargeable against the minor shall be fixed by the court rendering the judgment.