TLDR: To change font type for just the editor area, from the menu bar, go to
File->Settings->Editor->Font. Since you can’t edit the settings for the default theme/scheme, you first have to click “Save As…”, then you will be able to change the editor font.
Background: On Windows, I like the default font for Android Studio. On Ubuntu, the default font felt too cramped. I tried it for a week to see if I would get used to the “new” font, but at the end I was still longing for a different font. After looking through the the different mono-space fonts available by default, I’ve settled on the cleverly named “Source Code Pro” without trying the other system available fonts. The
I are clearly distinguishable in that font. How about now?