The default locale "" should be a UTF-8 locale.

"ls -q" (or "adb shell -tt ls") was mangling non-ASCII because mbrtowc
was returning multibyte characters as their individual bytes. This was
because toybox asks for "" rather than "C.UTF-8", and for some reason
we were interpreting that as "C" rather than "C.UTF-8".

Test: bionic tests, ls
Change-Id: Ic60e3b90cd5fe689e5489fad0d5d91062b9594ed