Kim Junsu is set to release his fifth solo studio album, “Gravity,” in June, agency Palmtree Island announced Tuesday. The upcoming album comes 10 years after his previous album, “Xignature,” and over four years after his third EP, “Dimension.” The veteran performer said in an interview last month that this new album might be his last. “Even if there is another, it could take quite some time,” he said, confiding that he has become cautious, caught between what is trending and what he can do best