[Animation Window] Adding a keyframe outside of the clip range and undoing does not resize clip.

Repro:
- Open attached project.
- Open scene 'Repro'
- Select game object 'Cube'
- In animation window, add a key frame at time 1:00 for property Position. Clip range should resize to 1:00 (good).
- Undo (Ctrl-Z).
- Clip range should remain at 1:00 (bad).

Repro: 5.6.0f1
Not Repro: 5.6.0b5, 5.5.2f1