“ In General.— Notwithstanding the second sentence of section 113 (a) of title 10, United States Code, the first person appointed, by and with the advice and consent of the Senate, as Secretary of Defense after the date of the enactment of this Act may be a person who is, on the date of appointment, within seven years after relief, but not within three years after relief, from active duty as a commissioned officer of a regular component of the Armed Forces. ”