SpriteUtility.GetSpriteUvs returns invalid UVs

1. Open ExampleScene
2. Click on SpriteObjTester
3. Check the section called Uvs

Expected result:
- Returns the uv coordinates of the sprite as if it was packed in the atlas.
Actual result:
- Returns either an empty array, or an array filled with the zero vector.

Tested on: 2017.1.0b1, 5.6.0f3s2, 5.5.3f1, 5.5.0f3s2