Update AudioEncoderFactoryTemplate implementation to expand unit tests to the new api.
Bug: webrtc:343086059
Change-Id: Ib63640de38aa15cc36067d5a3d1de2bf42cec313
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/353981
Reviewed-by: Jakob Ivarsson <jakobi@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42500}