Dave Grohl, Sam Smith, and Camila Cabello have signed on to perform from their living rooms as part of Sir Elton John’s star-studded coronavirus relief concert.The Rocket Man legend is leading the line-up for Fox Presents the iHeart Living Room Concert for America on Sunday – the same day the cancAll Postselled iHeartRadio Music Awards were set to be broadcast.He unveiled the initial bill of artists on Wednesday, when Mariah Carey, Alicia Keys, Billie Eilish, the Backstreet Boys, Tim McGraw, and Green Day’s Billie Joe Armstrong were all announced, and now fans have been given even more reason to tune in after rocker Grohl, Smith, and Cabello added their names to the hour-long event.Also taking part are Demi Lovato, Lizzo, H.E.R., Ciara, and