XR Visibility Mesh causes 0.2ms regression in GPU frametime on Standalone + OpenXR setups

Steps to reproduce:

1. Open an empty/new URP project
2. Install XR Plugin Management -> OpenXR for Standalone platforms (not Android)
3. Add a Monobehavior script to the scene and set XRSRPSettings.useVisibilityMesh = true; in Start()
4. Connect a Quest 2 device and open Quest Link
5. Enter Play mode and confirm that the Game view is streaming in stereo on your device
6. Connect the profiler to Play mode and ensure GPU profiling is enabled
7. After profiling, find RG_UberPost in the Profile's hierarchy view and notice the ~0.4ms value in frametime (XR Visibility Mesh pass should be nested under it)
   1. If XR Visibility Mesh is not visible, you may need to run adb shell setprop debug.oculus.visibilitymask.enable 1 in CMD
8. Save Profiler snapshot
9. Set useVisibilityMesh = false; (and visibilitymask.enable 0)
10. Profile again, and notice RG_UberPost frametime is listed as ~0.2ms (there should not be XR Visibility Mesh pass nested under RG_UberPost this time)

 

Expected result: Visibility Mesh provides a performance gain

Actual result: Visibility Mesh worsens performance within an empty scene