The film “Walter” centers on a curmudgeonly writer, Walter, portrayed by Bill Murray, who decides he's done with existence and leaves his spouse, Barbara, played by Noma Dumezweni, to deal with a four-foot-tall, quadrupedal, drooling predicament. She believes the ideal location for Apollo is with her longtime friend Iris, brought to life by Naomi Watts. Frankly, she’d prefer an alternative solution, but her compassio…