Post Malone whips through five decades of country music across 18 songs on F-1 Trillion, his first-ever country album. There’s a steel-soaked waltz, a glossy bit of effervescence, one or two boots-and-sawdust tributes to the ’90s, and several shows of understanding of 2000s country music. It’s all made contemporary by way of a youthful production team and 15 very willing collaborators. Related: Stunning Post Malone Facts — 11 Things Country Fans Need to Know With maybe one exception (listen and decide for yourself), Post’s song partners give 110 percent on F-1 Trillion. You can almost hear Dol…