[automerger skipped] C2SoftOpusEnc: Add support for a constant bitrate am:...

[automerger skipped] C2SoftOpusEnc: Add support for a constant bitrate am: 7cfafacb am: 5dab3faa -s ours

am skip reason: Merged-In I67234580650afae33b3f8e0a70a92633b506bc10 with SHA-1 7cfafacb is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/15153144

Change-Id: I85577babf9730531185cfb7712eb8eeb36d0d153