ANN ARBOR, Mich. — Democrat Kristen McDonald Rivet, who’s flaunted her pro-LGBT stance through social-media posts of herself at pride parades, is joining a Monday get-out-the-vote rally hosted by a bishop who’s come under fire for his anti-gay remarks. McDonald Rivet, a Michigan state senator vying for a congressional seat, is a “special guest” of Pentecostal…