Add minimum size of 1.0 to snap brush resizing

This is a tiny patch to !470 (merged). It adds a minimum size of 1.0 (instead of .01) when using the Snap action of the Change Primary Setting shortcut. The original MR was introduced to fix bug 361814, for the sake of pixel art, but from what I can tell, there isn't a difference between size .01 and 1.0 in this context, and most brushes don't seem to output anything at size .01 either.

Test Plan

Add a Change Primary Setting shortcut with action Snap in the canvas input settings, and observe the behavior.

Formalities Checklist

• I confirmed this builds.
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