codec2: add C2SoftAMR

Bug: 74770949
Test: setprop debug.stagefright.ccodec true
Test: stagefright -ao -N c2.google.amrnb.decoder /sdcard/clips/amrnb.wav
Test: stagefright -ao -N c2.google.amrwb.decoder /sdcard/clips/amrwb.wav

Change-Id: I7f4e986750c56b11d58d85f8521ff964db5fa313
3 files changed