ยง 214-b. Action to recover damages for personal injury caused by contact with or exposure to phenoxy herbicides. Notwithstanding any provision of law to the contrary, an action to recover damages for personal injury caused by contact with or exposure to phenoxy herbicides while serving as a member of the armed forces of the United States in Indo-China from January first, nineteen hundred sixty-two through May seventh, nineteen hundred seventy-five, may be commenced within two years from the date of the discovery of such injury, or within two years from the date when through the exercise of reasonable diligence the cause of such injury should have been discovered, whichever is later.