How to reproduce:

1. Open attached project
2. Open scene Scenes/SampleScene.unity
3. In the Hierarchy, select the New Sprite gameobject
4. In the Box Collider 2D or Rigidbody 2D inspector, expand the Info panel
- It animates when opening
5. Enter play mode
- Note that the Info panel is now collapsed
- This does not happen with non-animated Dropdown (like the Constraints in Rigidbody 2D)

- Reproducible as far back as 2017.1.1f1 (5d30cf096e79) and as recently as trunk