In any suit, action or proceeding involving the validity or enforcement of or relating to any contract of the regional housing authority, such authority shall be conclusively deemed to have become created as a public body corporate and politic and established and authorized to transact business and exercise its powers hereunder upon proof of the adoption of a resolution declaring the need for such authority by the legislative delegation of each of the counties within such authority.
A certificate stating that such resolution has been adopted shall be admissible in evidence in any suit, action or proceeding.