No person, firm or corporation shall exercise any franchise right or privilege mentioned in this Article, except insofar as they or it may be entitled to do so by direct authority of the Constitution of the State of California or of the United States, in the City of Berkeley, unless they or it shall have obtained a grant therefor in accordance with the provisions of this Article of this Charter and in accordance with the procedure prescribed by ordinance. Nothing in this Article contained shall be construed to invalidate any lawful franchise heretofore granted nor to necessitate the obtaining of a new franchise for a use for which a franchise holder shall have a valid unexpired franchise.