Add new variant us_rtl layout needle
    
    For RTL languages the keyboard icon and language indicator are
    the other way around, so we have different needles even for the
    US layout indicator which is otherwise the same in all langs.
    This is a variant needle for the new keyboard icon that showed
    up in Rawhide recently.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>