“509 (Top 24 at Disney’s Aulani Resort in Hawaii Part #1)” – “American Idol” returns to Aulani, A Disney Resort & Spa in Ko Olina, Hawaii, to kick off two nights of spectacular performances by the Top 24. Season 10 Idol alum Jimmie Allen serves as a mentor, offering sound advice to aspiring superstars vying for America’s vote, marking the first time overnight voting opens to audiences at home. Season 20 of “American Idol” airs SUNDAY, APRIL 10 (8:00-10:00 p.m. EDT), on ABC. (TV-PG, L) Watch episodes on demand and on