app.xr.input add event does not fire in pc.XRTYPE_AR (immersive-ar) mode

[josephrocca]

Description

Changing instances of pc.XRTYPE_VR to pc.XRTYPE_AR on this example: https://playcanvas.github.io/#/xr/vr-hands cause hands to no longer be detected.

Steps to Reproduce

1. Visit https://playcanvas.github.io/#/xr/vr-hands
2. Ctrl+F for XRTYPE_VR (there are two instances)
3. Change them to XRTYPE_AR and click the reload button
4. Observe that the hands are no longer there - the app.xr.input.on('add', ...) handler does not fire.

[Maksims]

Thank you for report. This has been fixed recently in this PR: #6069
It will be released to everyone with next engine release likely.

[josephrocca]

Nice, thanks!