[2D] The name and Texture fields are overlapping with each other in Secondary Textures

The name and Texture fields are overlapping with each other in Secondary Textures in the sprite editor window.

Steps to reproduce:
1. Create a new project with a 2D template.
2. Import any Sprite into the Unity project.
3. With the sprite selected in Assets, open Sprite Editor.
4. Sprite Editor > Secondary Textures > Secondary Textures > Add (+)
5. Observe the Name and Texture fields are overlapping with each other

Actual result: Name and Texture fields are overlapping with each other

Expected result: Name and Texture fields are well separated from each other.

Occurring in : 2021.0.a1, 2020.2.0b7, 2020.1.9f1, 2019.4.12f1.

Environment: Windows 10 and macOS 10.15