OSK: Add Swiss German and Swiss French keyboard layouts
The Swiss French and Swiss German keyboard layouts are a variant of the German QWERTZ keyboard layout. The difference between the Swiss German (de-CH) and the Swiss French (fr-CH) layout is that the German variety has the German umlauts (ä, ö, ü) accessible without dead keys, while the French version has the French accented characters (é, à, è) accessible in the unshifted state.
As these layouts don't seem to exist (yet) in the Android folder of the CLDR XML layout definitions available at www.unicode.org, and considering that the new Gnome OSK doesn't feature individual keys for accented characters, I used the German
data/osk-layouts/de.json file as a basis for both variants and changed the locale to "de-CH" and "fr-CH" and the name to "Swiss German" and "Swiss French" respectively at the end of each json file.