Unable to Launch Gazebo Simuation with laser_enabled and realsense_enabled flags set to true.

[brendoncintas]

Please provide the following information:

• OS: POP!_OS 20.04 (Focal Fossa)
• ROS Distro: Foxy
• Built from source or installed: Built From Source
• Package version: 1.0.8 (forked from foxy-devel)
• Real hardware or simulation: Simulation

Expected behaviour
When launching the gazebo.launch.py file from the husky_gazebo package using ros2 launch husky_gazebo gazebo.launch.py with no flags, the Husky spawns as expected without any onboard instrumentation. Adding flags the ros2 launch command (e.g. ros2 launch husky_gazebo gazebo.launch.py laser_enabled:=true or ros2 launch husky_gazebo gazebo.launch.py realsense_enabled:=true, the robot should also launch with the instrumentation, since we are overriding the default argument by passing the argument ABC_enabled:=true in our launch command, where ABC is realsense or laser.

Actual behaviour
When launching the gazebo.launch.py from husky_gazebo package with the instrumentation enable flags, the robot spawns with default parameters, regardless of if the flags are being passed in the launch file.

To Reproduce
Provide the steps to reproduce:
Launch gazebo.launch.py file from the husky_gazebo package using ros2 launch husky_gazebo gazebo.launch.py ABC_enabled:=true, where ABC is either laser or realsense.

Other notes
I've troubleshooted by:

1. Overriding the conditional statement to have default be true instead of false within husky_macro.urdf.xacro (the parameter for ABC_enabled, where ABC is realsense or laser, was changed from 0 to 1).
2. Reverting changes from Point 1, override the conditional statement to be true instead of false within spawn_husky.launch within husky_gazebo/launch/.
3. Reverting changes from Point 1 and 2, removing the conditional statement entirely and forcing the spawn within husky_macro.urdf.xacro.