The morning after the Academy Awards, Taika Waititi — the winner of the adapted screenplay Oscar for “Jojo Rabbit” — is drinking a Pedialyte. But however hungover the filmmaker might be, it does not stop him from hamming it up for a photo shoot. He writhes on a hotel room couch, folds himself into an armoire and holds out his Oscar with a look of mock terror on his face, as if he’s warding off a vampire with a cross.