Umm... this is basically the same as making ANY layout change in any Android application .
You don't have to do this in just Settings! This can be done in ANY app.
However, this resolution will be different in different devices like XXHDPI, XHDPI, and the XXXHDPI on the uber resolution devices. You really should just look at the border sizes (typically 10-20px per edge, depending on the resolution of the device.).
Oh, and don't forget to RESIGN the apk. Some devices may not play nice with an Altered Settings application that isn't signed with system-level keys.
That is all.