AGC2 is correctly (re)initialized when its config changes. This CL also improves the `AudioProcessingImpl::ApplyConfig` readability by defining operator!= also for the AGC1 config. Bug: webrtc:7494 Change-Id: I62068de32c941e6b18d4618c656f569647042345 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/187120 Commit-Queue: Alessio Bazzica <alessiob@webrtc.org> Reviewed-by: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#32402}