fix: network animator override

[mattwalsh-unity]

This addresses MTT-2530, that using an Animator Override controller breaks the "always sync" checkboxes in the editor. This was a pretty straightforward bugfix

I also create a NetworkAnimator test

Changelog

com.unity.netcode.gameobjects

• Added: The package whose Changelog should be added to should be in the header. Delete the changelog section entirely if it's not needed.
• Fixed: If you update multiple packages, create a new section with a new header for the other package.
• Removed/Deprecated/Changed: Each bullet should be prefixed with Added, Fixed, Removed, Deprecated, or Changed to indicate where the entry should go.

Testing and Documentation

• Includes integration tests.
• We should update the documentation to point out that (now) you can use the Animator Override controller

[mattwalsh-unity]

This fixes [MTT-2530]

[NoelStephensUnity]

Other than the SendMessagesAllowed perf hit, the rest looks good to me!