Merge \"libutils/Unicode.cpp: Correct length computation and add checks for...

Merge \"libutils/Unicode.cpp: Correct length computation and add checks for utf16->utf8 am: 53473c16 am: 41e6690d am: 29ccafe5 am: fd7bd2df am: 498ffa62 am: 5e4ebd02 am: d837e743 am: 6025b216 am: a73f7e5e am: 79a3c84c am: 17cd63d0  -s ours am: b4c163b7 am: 127876e0\" into nyc-mr1-dev-plus-aosp
am: 560a3fdd

Change-Id: I413d94aaf1c5a2816b59d90caae878d93f374816