DO NOT MERGE libutils/Unicode.cpp: Correct length computation and add checks for utf16->utf8 am: 5fce0542b6 am: d0ad14ca21 am: 3841c92912  -s ours am: 247ac63c69  -s ours am: 6179f1a56e
am: 451f4b3d04

Change-Id: I1781e52845996557f9f6a7e8b359e1d698e38e45