This activity points to the system settings page for enabling input
methods. This is purely a shortcut but is expected by many users.
It could be made more useful in the future or hidden whenever the
keyboard is enabled.
A new option changes the "change_method" into the new
"change_method_prev". It switch to the previously used input method.
A long press on "change_method_prev" sends "change_method".
A new section is added in the settings and existing options are moved.
