An Albert Brooks doubleheader is presented tonight on TNT, and the network is featuring two of his less frequently televised comic experiments. First up is this 1979 movie, his directorial and starring debut, which was way, way ahead of its time. In 1973, PBS presented An American Family, one of TV’s first “reality shows,” a documentary recounting the everyday private life of a middle-class suburban family called the Louds. Six years later, Brooks presented this satire, playing