James Cameron's "Avatar: Fire and Ash" lands in theaters Dec. 19 — 16 years after the sci-fi franchise's landmark first entry and seven years after most of its stars completed their performance capture work. As they began a globe-trotting publicity tour, AP entertainment editor Ryan Pearson sat down in Los Angeles with Cameron and actors Zoe Saldaña, Sigourney Weaver, Stephen Lang, Sam Worthington, Oona Chaplin, Trinity Jo-Li Bliss, Jack Champion and Bailey Bass. They shared stories of their