Extend Android language mappings for translated metadata

This is likely still not complete, but with this at least most of Itinerary's metadata translations are accepted during upload to the Google Play store (the remaining ones are rejected for different reasons). F-Droid seems considerably less picky about this, and works with either form.

@apol do you remember why the ca -> ca-ES mapping was there? The Play Store rejects that and insists on just ca.