The making of or failure to make an advance health care directive, to request an order or to designate or disqualify a health care representative in accordance with this chapter shall not affect in any manner the sale, procurement or issuance of a policy of life insurance, nor shall it be deemed to modify the terms of an existing policy of life insurance. No policy of life insurance shall be legally impaired or invalidated in any manner by the withholding or withdrawal of life-sustaining treatment from an insured individual, notwithstanding a term of the policy to the contrary.