Any policy or contract of liability insurance providing coverage for liability sold, issued or delivered in this state to any owner of lands covered under the provisions of this article shall be read so as to contain a provision or endorsement whereby the company issuing such policy waives or agrees not to assert as a defense on behalf of the policyholder or any beneficiary thereof, to any claim covered by the terms of such policy within the policy limits, the immunity from liability of the insured by reason of the use of such insured's land for recreational, wildlife propagation or military purposes, unless such provision or endorsement is rejected in writing by the named insured.