The ext.uls.buttons style can be removed but Translate extension use that.
Once it is separated we can remove it from ULS.
Testplan:
Use ULS settings and notice the style difference of buttons, checkboxes
and radio buttons. No functionality should be affected and UI should not
be broken in any ways.
This was once attempted in Id186ece6513f154e0388bc4170c21bdabb59038a
but we had to revert because of incompleteness
Bug: T52599
Bug: T127020
Change-Id: Ibbb2068b5036537f298fad6c49169a5b986304d5
a3c63f1efc