Elaine Low Senior TV WriterNetflix, in its third quarter earnings report Tuesday, touted “The Old Guard” as its most popular title of the summer quarter.According to the streamer, 78 million subscriber households tuned in to watch the action thriller, directed by Gina Prince-Bythewood and starring Charlize Theron, in its first four weeks on the platform.Other Netflix original features that proved popular included Jamie Foxx starrer “Project Power,” which drew 75 million households in the same