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 am: dc5a96f5b3 am: 1aad4b61cb  -s ours am: 8170f506f7
am: 8ea5dfee6b

Change-Id: Ifc8ee3c994fd58a0a8246c66898c060530f67c91