Leena Tailor As she slowly awakens from the “dream” of working with director Steven Spielberg on “West Side Story,” Maddie Ziegler is teasing some of the upcoming musical’s standout scenes, including the iconic “Dance at the Gym” number. The “Dance Moms” alum stars as Velma in Spielberg’s film adaptation of the 1957 Broadway musical, about two teenagers (played by Ansel Elgort and Rachel Zegler) of different ethnicities, who find love in New York.“It’s always nerve-wracking to do a remake of