In any action or proceeding involving the validity or enforcement of, or otherwise relating to, any contract of an authority, the authority shall be conclusively deemed to have become established and authorized to transact business and exercise its powers under this article upon proof of the adoption of a resolution by the governing body declaring the need for the authority. Such resolution shall be deemed sufficient if it declares that there is need for an authority and finds in substantially such terms as appear in subsection (a) of Code Section 8-3-5, no further detail being necessary, that either or both of the conditions enumerated in that subsection exist in the city or county, as the case may be.
OCGA § 8-3-6