Divide dough into 2 equal portions; roll out each portion into an 11-inch circle (about 1/4 inch thick) on work surface coated with cooking spray. Let dough rest while preparing sauce and toppings.
Cook tomato sauce, uncovered, in a saucepan over medium-high heat 2 to 3 minutes or until slightly thick.
Coat grill racks with cooking spray; grill 1 portion of dough over medium-low heat 2 to 3 minutes or until browned. Turn dough. Spread half of tomato sauce over cooked side of dough. Top with half each of cheese, mushrooms, onion, and olives. Close grill lid; grill 4 minutes or until cheese melts and bottom of crust is browned. Remove from heat; repeat procedure with remaining ingredients. Cut each pizza into 4 slices.