Feature/fix xr prefab (#265)

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## [TICKETID](https://ready-player-me.atlassian.net/browse/TICKETID)

## Description

-   fixed bone references on xr template and added tests 

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## How to Test

-   Add steps to locally test these changes

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## Checklist

-   [ ] Tests written or updated for the changes.
-   [ ] Documentation is updated.
-   [ ] Changelog is updated.

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