fix(autoware_motion_velocity_planner_common_universe): check optional…

… before accessing (autowarefoundation#10183)

* Update polygon_utils.cpp

fix bug-prone code

Signed-off-by: Y.Hisaki <yhisaki31@gmail.com>

* Update polygon_utils.cpp

---------

Signed-off-by: Y.Hisaki <yhisaki31@gmail.com>

planning/motion_velocity_planner/autoware_motion_velocity_planner_common_universe/src/polygon_utils.cpp

@@ -150,6 +150,7 @@ std::optional<std::pair<geometry_msgs::msg::Point, double>> get_collision_point(
       max_collision_point = poly_vertex.point;
     }
   }
+  if (!max_collision_point.has_value() || !max_collision_length.has_value()) return std::nullopt;
   return std::make_pair(
     *max_collision_point,
     autoware::motion_utils::calcSignedArcLength(traj_points, 0, collision_info.first) -