Fix off-by-one in ReadBuildIDFromMemory.

This was sometimes causing build ids to be truncated, probably because
of memory corruption in std::string. A similar off-by-one was fixed in
ReadBuildID in aosp/939619.

Bug: 129873279
Change-Id: I401fe7f991dbd135f5b4836381b48ea3c6a2243f
2 files changed