Cherien Dabis knew she wanted to bring more attention to her film, and for that, she needed star power. Her Sundance drama, All That’s Left of You — Jordan’s Oscar submission for best international feature this year — chronicles multiple generations of a displaced Palestinian family. But amid heated debates in the U.S. over the Israel-Gaza war, the director and actor felt her project was being overlooked. Enter Mark Ruffalo and Javier Bardem. On Sept. 24, the A-listers, established supporters of the Palestinian cause, formally joined the feature as executive producers. In their roles, they’re expected to do media for...