override utf8 max len, badly set (MB_CUR_MAX=1)

The MB_CUR_MAX macro defines an integer expression giving the maximum
number of bytes needed to represent a single wide character in the
current locale.  It is locale dependent and therefore not a compile-
time constant. (except for bionic)

Change-Id: Ic44a72ec7fb6cfe011009762d8ecfa272beab569