"DREAM TEAM: HOW MICHAEL, MAGIC, LARRY, CHARLES, AND THE GREATEST TEAM OF ALL TIME CONQUERED THE WORLD AND CHANGED THE GAME OF BASKETBALL FOREVER." By Jack McCallum. Ballantine Books. $28."IGNITING THE FLAME: AMERICA'S FIRST OLYMPIC TEAM." By Jim Reisler. Lyons Press. $25.LONDON -- The evolution of the Olympics through the last 100-plus years can be compared to having your backyard barbecue turn into restaurant row in Beverly Hills. The trappings of innocence and just having good old-fashioned fun have been replaced by unrestrained jingoistic marketing and brand identification.The true sports fan holds to the ideal that the Games are about the athletes. But they're not. The focus is on branding that will lead to the eventual sale. It happens on all levels: Even photojournalists at the Games are lent lenses worth $5,000 and more by Canon and Nikon in the hope that their distinctive color will be picked up by television or in the background of photos. Then, someone watching the Games might think, "If the best photographers in the world use that lens, I should do the same."