How to reproduce:
1. Open the attached project (case_1149894_TilePaletteTest)
2. Go to Window -> Package Manager and install 2D Animation package
3. Go to Assets -> Create -> Sprites -> Square and create the new Sprite
4. Go to Window -> 2D -> Tile Palette and create a new Tile Map
5. Add the Sprite to the Tile Map in the Tile Pallete

Expected result: Tile Palette displays the Sprite correctly
Actual result: The Sprite in Tile Palette flickers

Reproducible with Unity versions: 2018.3.14f1, 2018.4.0f1, 2019.1.1f1

Reproducible with package versions: 2.0.0-preview.2, 2.1.0-preview.1, 2.1.0-preview.2

Not reproducible with package versions: 1.0.16-preview.2, 2.0.0-preview.1

Notes:
- In versions 2019.1.0a1-2019.1.0b4, 2019.2.0a1 - 2019.2.0a14 and 2019.3.0a1 - 2019.3.0a2 installing 2D Animation package produces missing type,namespace or definition errors, therefore the issue cannot be reproduced
- 2.1.0-preview.1 was introduced before 2.0.0-preview.2, therefore changes made in that version might have caused the regression