A group of 300 A-list Hollywood celebrities—including Ben Stiller, “Hunger Games” Jennifer Lawrence, Meryl Streep, Liam Neeson, Kevin Bacon, and Julia Louis-Dreyfus—is threatening to take industrial action if their demands on key issues are not met. They include better protection against artificial intelligence (AI) celebrity cloning, a “seismic realignment” in minimum pay, an increase in media residuals,…