Depth-only point cloud launch file for Non-RGB PrimeSense device.

[TiNredmc]

Some Depth camera based on PS1080 SoC such as Asus Xtion and (some) Xtion Pro don't come with RGB camera.

The original 'camera_with_cloud' launch file requires the missing RGB color stream, which Xtion and (some) Xtion Pro don't provide. This make point cloud topic publish no message at all.

Solving by changing depth_image_proc::PointCloudXyzrgbNode to depth_image_proc::PointCloudXyzNode and remove all RGB related topic remap in launch file. Resulted in the new launch file named 'camera_with_cloud_norgb'. Modified from 'camera_with_cloud' launch file.

I tested with these following device and environment

• Asus Xtion (Possibly pre-production or custom made unit)
• ROS2 Humble
• Ubuntu 22.04 on WSL2
• USBIP

[mikeferguson]

This looks good as a temporary solution - we will eventually remove these launch files once we can fully implement openni2_launch (#120) - but that will likely be a couple more months for rolling, and will go into the J-turtle release