Amanda Micheli documents Jennifer Lopez’s journey to performing at the 2020 Super Bowl in the moving documentary “Halftime,” streaming on Netflix Tuesday. Though the film focuses on Lopez’s preparations for the performance, including her awards season run for the 2019 film “Hustlers,” “Halftime” also serves as a look back at Lopez’s remarkable career, as Jenny From the Block transformed into the global phenomenon J.Lo. “Halftime” offers a peek behind the curtain at the grueling rehearsals for the halftime show, which was a run through the greatest hits of her career, a collaboration with Shaki…