[2D] [Sprite Editor] [Secondary Texture] Name for Secondary Texutre is only saved after hitting Enter or clicking out of field

Steps to Repro:
1. add a sprite to the project
2. select the sprite and open the Sprite Editor window
3. go to the Secondary Texture module
4. click on the + button to add a new Secondary Texture
5. enter text into the Name field then click on the button to select a Texture (do not press Enter)
6. select a a Secondary Texture

Result: The Secondary Texture is selected but the text for the Name field is empty (text was not saved). The user must press Enter or click outside of the Name field to save the name.