Fix: Correct URDF path in demo_launch.py (ros2#5874)

* Fix: Correct URDF path in demo_launch.py 

This pull request resolves a launch file error by correcting the path used to find the robot's URDF file. The previous configuration was causing a TypeError because FindPackageShare was being called with too many arguments.

The correct implementation separates the package name from the file path, allowing PathJoinSubstitution to correctly combine them. This ensures the robot_state_publisher can successfully locate and load the r2d2.urdf.xml file.

Signed-off-by: Hemand Sunny <[email protected]>
Signed-off-by: Alejandro Hernández Cordero <[email protected]>
Co-authored-by: Alejandro Hernández Cordero <[email protected]>

Author: expozedrookie

source/Tutorials/Intermediate/URDF/launch/demo_launch.py

@@ -8,7 +8,7 @@
 def generate_launch_description():
     use_sim_time = LaunchConfiguration('use_sim_time', default='false')
     urdf = FileContent(
-        PathJoinSubstitution([FindPackageShare('urdf_tutorial_r2d2', 'r2d2.urdf.xml')]))
+        PathJoinSubstitution([FindPackageShare('urdf_tutorial_r2d2'), 'r2d2.urdf.xml']))
 
     return LaunchDescription([
         DeclareLaunchArgument(