He’s one of the biggest pop stars in the world, but Post Malone’s new album, “F-1 Trillion,” features his duets with some of the biggest names in the country, including Luke Combs, Blake Shelton, Morgan Wallen and Dolly Parton. Correspondent Anthony Mason visits Malone in Nashville to talk about his acceptance among country music fans; how he handled being called a “one-hit wonder” after his debut with the 2015 hip-hop smash “White Iverson”; and how he recovered from a downward spiral he experienced in the midst of his success.