Button label goes bold after first tap on mobile (but then unbold again)

On desktop we support focus via tabbing which sets button labels to bold, but there is a bug on mobile. 

When a button is tapped on mobile there is a bad interaction with the desktop focus code where the label becomes bold. Note that tapping it again unbolds the label, and then it remains unbold.

This can be repro'd on mobile device emulation mode.
