Drop downs for text settings too tall

This is what I see on paragraph settings in Twenty Twenty:

![image](https://user-images.githubusercontent.com/253067/71903198-7ef51f80-315b-11ea-863e-812e4ca257b2.png)

Here it is in Twenty Nineteen:

![image](https://user-images.githubusercontent.com/253067/71903431-fd51c180-315b-11ea-95f3-94bab6bbd05f.png)
