LAS VEGAS — This is how the U.S. Olympic men’s basketball team took the floor for warmups before an exhibition game in Abu Dhabi: Stephen Curry opened with a layup, followed by ones from Tyrese Haliburton, Anthony Edwards and Derrick White, and then a short jumper from Devin Booker. “He’s still LeBron,” U.S. assistant coach Erik Spoelstra said. “And from …