(12) The term “industry or activity affecting commerce” means any activity, business, or industry in commerce or in which a labor dispute would hinder or obstruct commerce or the free flow of commerce, and includes any activity or industry “affecting commerce” within the meaning of the Labor Management Relations Act, 1947 [ 29 U.S.C. 141 et seq.], or the Railway Labor Act [ 45 U.S.C. 151 et seq.].