I want to add an HTTPS listener to my AWS Application Load Balancer. I see from this thread that it's not possible without a custom domain (and the certificate that authenticates it). My question is why? Couldn't there be a certificate belonging to AWS, and it would certify, when people connect to my ALB, that "yes you are indeed talking in HTTPS with domain blabla.us-west-1.elb.amazonaws.com"?