C2SoftOpusEnc: Fix integer overflows leading to crash by changing data type Bug: 211910627 Test: POC in bug descriptions Test: atest VtsHalMediaC2V1_0TargetAudioEncTest Test: atest CtsMediaTestCases:EncoderTest Change-Id: I72fee83ae27d3f446b1584fd4fd047e93a0a01d9 (cherry picked from commit d6ec069ca392aeef135c6671fc9701485bd1c60c) Merged-In: I72fee83ae27d3f446b1584fd4fd047e93a0a01d9