🐛 Bones do not inherit step interpolation in-game

[SnaveSutit]

Describe the bug
When animating in-game, children of bones with step interpolation keyframes do not use step interpolation (They interpolate over 1 tick instead of 0 ticks).

To Reproduce

1. Create a Blueprint with a hierarchy of bones like so:

   parent_bone:
     - child_bone:

2. Create an animation with step keyframes for parent_bone, and no keyframes for child_bone.
3. Export the Blueprint, then summon the Rig in-game.
4. Start the animation
5. Observe the child interpolating smoothly, and the parent interpolating instantly.

Expected behavior
The child_bone should interpolate the same way the parent does, instantly.

Desktop (please complete the following information):

• Animated Java Version: 1.6.4