`handleNewKeyboards()` makes sure that new enabled keyboards (i.e. `keyboard.layout._`) are marked in the global `enabledKeyboardNames` variable and thus I make sure the `keyboard.current`'s keyboard group is enabled.

When the user switches keyboard layouts from the keyboard, the `keyboard.current` is set at [#L729](https://github.com/mcirlanaru/gaia/blob/cd807a8508a4dee47989867b9b6bbfc3a1d7c7be/apps/keyboard/js/keyboard.js#L729), I will check to make sure the observer doesn't run `setKeyboardName()` and `handleNewKeyboards()` twice.