AnimComponentLayer.getAnimationAsset always returns {"asset": null} on template instances created at runtime

[Mintytorus]

Description

When instantiating an entity with an Anim component from a template at runtime, AnimComponentLayer.getAnimationAsset never returns a valid animation asset - it always returns an object of the form {"asset": null}. I have filed a separate issue due to this differing from the documentation (which suggests this should return a pc.Asset instance).

Example project:
https://playcanvas.com/project/1240526 (published build)

Steps to Reproduce

1. Create an entity with an Anim component and populate with assets (a render component, an anim graph with a default animation state, an animation for that state)
2. Create a template from that entity
3. Instantiate the template at runtime (i.e. call templateAsset.resource.instantiate(), don't place it in the editor)
4. Try and get the animation for the default layer by calling AnimComponentLayer.getAnimationAsset

Expected result: Some kind of usable asset (either a pc.Asset or at least an asset id)
Observed result: A Javascript object {asset: null}

Note that for an entity instantiated in the editor (either from the same template or just manually) will return {asset: [ASSET ID NUMBER]} instead.