allow some time for ui to receive and write param

selfdrive/controls/lib/longitudinal_planner.py

@@ -98,6 +98,7 @@ class LongitudinalPlanner:
     for m in messaging.drain_sock(carState_sock, wait_for_one=False):
       if any(not be.pressed and be.type == ButtonType.gapAdjustCruise for be in m.carState.buttonEvents):
         self.personality = (self.personality - 1) % 3
+        self.param_read_counter = 0
 
     self.param_read_counter += 1
     self.mpc.mode = 'blended' if sm['controlsState'].experimentalMode else 'acc'