Fix potential overflow in WAV extractor Bug: 170583712 Test: fuzzer poc, atest DecoderTest#testDecodeWav Change-Id: I73edd5fc0da80dc2cdd26c6fcd09496b2c828ba9 Merged-In: I73edd5fc0da80dc2cdd26c6fcd09496b2c828ba9 (cherry picked from commit 66c0c4274d932716b552cdd1d922040bbab41c5f)