Rock What You Got Inpop Records The front cover speaks volumes — a turntable boombox sits atop an amplifier; on one of its speakers is a tracing of a spiky-haired girl shouting into a megaphone. There you go — that’s “Rock What You Got,” Christian superstar band Superchick’s newest album. Every song is a candy-crunch, pop-a-tronic sing-along anthem. You’ll feel…