Jennifer Maas TV Business Writer The last-ever episode of “9-1-1” on Fox airs Monday, and it’s a bittersweet occasion for Oliver Stark, who has starred as Evan “Buck” Buckley on the Ryan Murphy-produced first-responder drama since its debut six seasons ago. While the show is ending its run on one network, it will be alive and well next season on ABC — the broadcaster that is owned by Disney, the parent company of “9-1-1” studio 20th Television, which not too long ago was owned by Fox — so Stark isn’t saying goodbye to his character, so much as a family he and his co-stars have established behind-the-scenes. Here, Stark discusses with Variety his reaction to the move to ABC for Season 7, and if he thinks spinoff “9-1-1: Lone Star” (which also hails from 20th Television) remaining at Fox for its fifth season means the chance at another crossover episode between the two series is slim.