DO NOT MERGE libutils/Unicode.cpp: Correct length computation and add checks for utf16->utf8 am: 2806397d1e am: 8c9d02551c am: 28f28ce635  -s ours am: f611765aaf
am: 207717bde6

Change-Id: I88e2cafcf84bff82c29725dd484103dabf248a8b