Revert "Make VideoStreamEncoder::ReconfigureEncoder always call ConfigureQualityScaler."
Revert "Make VideoStreamEncoder::ReconfigureEncoder always call ConfigureQualityScaler."

This reverts commit f394f65b7195a5f9f71c9f0dec3bb68300590b5b.

Reason for revert: Breaks downstream project.

Original change's description:
> Make VideoStreamEncoder::ReconfigureEncoder always call ConfigureQualityScaler.
> 
> In addition restore call to ConfigureQualityScaler in SetSource, which
> is needed if degradation preferences change mid-stream.
> 
> Fixes a regressions from https://webrtc-review.googlesource.com/70740,
> The encoder's GetScalingSettings may depend on arguments to
> InitEncode, so configuring the quality scaler only at encoder creation
> time isn't enough.
> 
> Bug: webrtc:8830
> Change-Id: I48f66cde219c56272f44441fdb26ec64c6002068
> Reviewed-on: https://webrtc-review.googlesource.com/72000
> Reviewed-by: Åsa Persson <asapersson@webrtc.org>
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#22993}

TBR=nisse@webrtc.org,asapersson@webrtc.org

Change-Id: I8c1c12fb53a1bfd6d03c54b93dac6033b7cce081
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:8830
Reviewed-on: https://webrtc-review.googlesource.com/72220
Reviewed-by: Mirko Bonadei <d2c43c210eae6feef04f53bae50885e8152edcca@webrtc.org>
Commit-Queue: Mirko Bonadei <d2c43c210eae6feef04f53bae50885e8152edcca@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#23011}
ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc