In the "Sprite Editor" window, Unable to add and remove Texture from the List under "Secondary Texture" panel. Also "Add to List" and "Remove Selection from List" buttons are overlapping with "Texture List", refer attached video.

Steps to repro:
1. Create a new project with 2D Template.
2. Import a sprite in the project window
3. Inspector > Sprite Editor
4. Switch to "Secondary Texture" mode
5. Secondary Texture Panel (right-bottom corner) > Add 3 Textures in the list

Actual Result:
Unable to add and remove more than one Texture in the list under Secondary Texture panel

Expected Result:
Texture added and removed gracefully in the list, Also add and remove list buttons are doesn't overlap with Texture List

Occurring on:
2020.2.0a13

Working fine on:
2020.2.0a12, 2020.1.0b10

Package found version: 1.0.0

Environment:
Windows 10 and macOS 10.14