Fix: SpellChecker subtype label cannot be updated.

"Use system languages" is always displayed independent from the
selected value.
This happens due to inverted if-condition that has been introduced in
I0ed71bbb580e3547d97e321799ac2b77b1f284a3

Bug: 28204608
Change-Id: I9f0390242cb5ed4960c06eb3d0a4ade7a66143a5