“J.K. Rowling: A Year in the Life” (8 p.m., ABC): What’s it like to be the

“J.K. Rowling: A Year in the Life” (8 p.m., ABC): What’s it like to be the gatekeeper to a fantasy world enjoyed by muggles everywhere? “J.K. Rowling: A Year in the Life” is an intimate profile of the author of the “Harry Potter” novels. Elizabeth Vargas reports.