Avoid cluster set up at max bitrate at start

webrtc/modules/congestion_controller/include/congestion_controller.h

Index: webrtc/modules/congestion_controller/include/congestion_controller.h
diff --git a/webrtc/modules/congestion_controller/include/congestion_controller.h b/webrtc/modules/congestion_controller/include/congestion_controller.h
index b70899d84beac91b2ea36871e333005674f8d87c..1c8246004659d4067f97182fee5b6286f1673072 100644
--- a/webrtc/modules/congestion_controller/include/congestion_controller.h
+++ b/webrtc/modules/congestion_controller/include/congestion_controller.h
@@ -123,6 +123,7 @@ class CongestionController : public CallStatsObserver, public Module {
   const std::unique_ptr<RateLimiter> retransmission_rate_limiter_;
   RemoteEstimatorProxy remote_estimator_proxy_;
   TransportFeedbackAdapter transport_feedback_adapter_;
+  int start_bitrate_bps_;
   int min_bitrate_bps_;
   int max_bitrate_bps_;
   rtc::CriticalSection critsect_;