She’s best known as one half of a powerhouse duo, but AJ Michalka is about to go solo in a big way, the 16-year-old singer beamed, revealing that she’s set to appear in Peter Jackson’s “King Kong” follow-up, “The Lovely Bones.” “It’s like a dream role,” she enthused, nearly jumping up and down with excitement. “I’m playing the best friend of the girl who gets murdered. I was flipping out [when I heard I won the part]. I’m really, really stoked.”