Revert "Add signed integer overflow checking to flac."

This reverts commit ab37b6247df0e8c4ec0ccaa870e667f62c74975b.

Bug: 11458679
Change-Id: Idac3bd854ebe826008c4059f117e96f67e4cb69a
Merge remote-tracking branch 'aosp/kitkat-mr2-release' into kitkat