The group life insurance policy must contain a provision that the validity of the policy may not be contested, except for nonpayment of premium, after it has been in force for two years from its date of issue; and that a statement made by a person insured under the policy relating to that person’s insurability may not be used in contesting the validity of the insurance with respect to which the statement was made after the insurance has been in force for a period of two years during the person’s lifetime or unless it is contained in a written instrument signed by the person.