Hayden Christensen and Diego Luna have never met, but as Christensen puts it, they’ve occupied the “same galaxy” for years. Christensen rocketed from teenage obscurity in Canada when George Lucas cast him as Anakin Skywalker for 2002’s “Star Wars: Episode II — Attack of the Clones” and 2005’s “Revenge of the Sith,” which chronicled the young Jedi’s transformation into the iconic villain Darth Vader. The Mexican-born Luna — who rose to prominence in Alfonso Cuarón’s 2001 coming-of-age masterpiece “Y tu mamá también” — joined “Star Wars” for 2016’s “Rogue One,” a prequel about the band of rebel spies, led by Luna’s Cassian Andor, that steal the plans for the Death Star.