Fox says “American Idol” will air its 15th and final season next year. The once-blockbuster singing contest, which launched the careers of Kelly Clarkson,Carrie Underwood and Jennifer Hudson, has seen its audience dwindle and age. “Idol” will return in January for its 15th and final season with host Ryan Seacrest and judges Jennifer Lopez, Keith … More Last Season Of ‘American Idol’ Set For Fox’s 2015-16 Lineup