New api ensures field trials are available at construction time of the AudioProcessing object.
This would allow AudioProcessing implementation to use propagated field trials during construction.
Also, short term, it ensures AudioProcessing is constructed after global field trials are set.
Bug: webrtc:369904700
Change-Id: If3d00c8a3a509299cd0915d55f13a9a3ce4a7140
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/367201
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43340}