Head lock mode is not visible in camera_viz

[Tomico-DEV]

Describe the bug
When a display's placement mode is set to head in camera_viz, the display is not visible.

To reproduce
Steps to reproduce the behavior:

1. Run camera_viz with any configuration that uses the head placement mode (eg. config/synthetic_xr_3up.yaml)
2. Start teleop session
3. Notice that the head tracking display is not visible

Expected behavior
The head tracking display should be visible and positioned at a constant and relative position and orientation to the headset at the all times.

Observed behavior
The head tracking display is not visible.

Platforms

• Isaac Teleop Version: 1.5.x
• OS: Ubuntu 24.04, ARM64 (Jetson Thor)
• XR Device: Pico 4 Ultra