Revert "Moved BitrateConfig out of Call::Config."

This reverts commit 5897fe27abcbe70f706cc23adc26147e0581f97e.

Reason for revert: Breaking internal builds

Original change's description:
> Moved BitrateConfig out of Call::Config.
> 
> This prepares for a CL extracting the bitrate configuration logic from
> the Call class.
> 
> Also renaming BitrateConfig to BitrateConstraints.
> 
> Bug: webrtc:8415
> Change-Id: I7e472683034c57bdc8093cdf5e78e477d1732480
> Reviewed-on: https://webrtc-review.googlesource.com/54400
> Commit-Queue: Sebastian Jansson <srte@webrtc.org>
> Reviewed-by: Stefan Holmer <stefan@webrtc.org>
> Reviewed-by: Niels Moller <nisse@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#22104}

TBR=nisse@webrtc.org,stefan@webrtc.org,srte@webrtc.org

Change-Id: I598040edba7f1ff8b39d2d9c3c3ceca5627aaa0c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:8415
Reviewed-on: https://webrtc-review.googlesource.com/55740
Reviewed-by: Lu Liu <lliuu@webrtc.org>
Commit-Queue: Lu Liu <lliuu@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22106}
diff --git a/media/engine/webrtcvideoengine.h b/media/engine/webrtcvideoengine.h
index f481b8b..f126493 100644
--- a/media/engine/webrtcvideoengine.h
+++ b/media/engine/webrtcvideoengine.h
@@ -501,7 +501,7 @@
   // See reason for keeping track of the FlexFEC payload type separately in
   // comment in WebRtcVideoChannel::ChangedRecvParameters.
   int recv_flexfec_payload_type_;
-  webrtc::BitrateConstraints bitrate_config_;
+  webrtc::Call::Config::BitrateConfig bitrate_config_;
   // TODO(deadbeef): Don't duplicate information between
   // send_params/recv_params, rtp_extensions, options, etc.
   VideoSendParameters send_params_;