“As he evolved, the boos gave way to cheers and rivalries turned into friendships,” Earnhardt says in the nearly four-minute video produced by Amazon Prime. WASHINGTON — Dale Earnhardt Jr. paid tribute to his rival-turned-friend over the weekend, narrating a nearly 4-minute video about Kyle Busch for Amazon Prime. The streaming service released the video tribute Sunday night, just four days after Busch’s sudden death at the age of 41. Amazon Prime has been broadcasting NASCAR races since last year, with Earnhardt serving as one of two color commentators. The video titled “Dale Jr. remembers his friend Kyle” begins with…