Fix openarm_bimanual.usd colliders

[umegan]

Fix Collision Geometry: Switch to Convex Decomposition

What I Did

Updated the collision approximation for three primitives from Convex Hull to Convex Decomposition for better accuracy:

world/collisions
openarm_left_link_7/collisions
openarm_right_link_7/collisions

Why

Convex Hull created large, inaccurate collision bounds (visible in the "Before" image) which was interfering with path planning. Convex Decomposition provides a much tighter fit.

Visuals

Before

After

[gunyarakun]

Thank you for your contribution!
We can't merge it right away, but we're thinking we'd like to merge it in the next version.

[umegan]

Sounds great! Thanks for the feedback and for planning to include it in the next version.