The aacDecoder_DecodeFrame function takes a size in numbers of
samples (INT_PCM), not a number of bytes. Using a number of
bytes caused the FDK to believe the array was larger than it
really was. Therefore on invalid frames, it would try to
clear a size larger than was really available, causing an OOB
crash.
Bug: 161014225
Test: check clusterfuzz results for case 6217304556437504
Change-Id: I9278898a17c1c961c568e841c6037d0c14bcc8b4