This replaces the "disable accent keys" checkbox.
The default should work for anyone: Accents will be hidden unless the
user has the french language installed.
The value "show every accents" is useful for versions of android that
don't have subtypes.
This was a half-finished feature:
- Dangerous when typing passwords
- Caused crash on some devices
- Ugly (on its own but also blinking when sliding and not fixed in size)
