This is a pure noop refactor that removes duplicated state.
It also correctly keeps track of generated samples when transitioning from CNG to expand mode when CNG timeout is used.
Bug: webrtc:12790
Change-Id: Ieca559bd771c42566e5d4f8837235cb25b1420bf
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/293862
Commit-Queue: Jakob Ivarsson <jakobi@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39334}