Propagate is_bw_limited flag with bw allocation everywhere it's copied

Bug: webrtc:11015
Change-Id: Ie971d29d8a8d140ba120a51dd3920291034a4d48
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/166526
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30325}
diff --git a/video/encoder_bitrate_adjuster.cc b/video/encoder_bitrate_adjuster.cc
index 5fa7434..5af9128 100644
--- a/video/encoder_bitrate_adjuster.cc
+++ b/video/encoder_bitrate_adjuster.cc
@@ -289,6 +289,10 @@
     }
   }
 
+  // Since no spatial layers or streams are toggled by the adjustment
+  // bw-limited flag stays the same.
+  adjusted_allocation.set_bw_limited(rates.bitrate.is_bw_limited());
+
   return adjusted_allocation;
 }
 
diff --git a/video/video_stream_encoder.cc b/video/video_stream_encoder.cc
index 52dc53f..2a6f14c 100644
--- a/video/video_stream_encoder.cc
+++ b/video/video_stream_encoder.cc
@@ -183,6 +183,7 @@
       }
     }
   }
+  new_allocation.set_bw_limited(allocation.is_bw_limited());
   return new_allocation;
 }
 }  //  namespace