C2SoftAmrWbEnc:  Fix integer overflows leading to crash by changing data type

Bug: 218983266

Test: POC in bug descriptions
Test: atest VtsHalMediaC2V1_0TargetAudioEncTest
Test: atest CtsMediaTestCases:EncoderTest
Change-Id: I288e171aa9fc607f11a71abfbced9ab9d3d9f84f
2 files changed