add parameter to enable velocity smoothing

Signed-off-by: Maxime CLEMENT <[email protected]>

autoware_launch/config/planning/scenario_planning/lane_driving/motion_planning/motion_velocity_planner/motion_velocity_planner.param.yaml

@@ -1,5 +1,3 @@
 /**:
   ros__parameters:
-    stop_line_extend_length: 5.0
-    system_delay: 0.5
-    delay_response_time: 0.5
+    smooth_velocity_before_planning: true  # [-] if true, smooth the velocity profile of the input trajectory before planning