Revert "Always offer transport sequence number header extension for audio"

This reverts commit fd965c008c7bc395bb276f260262ac11ccd25406.

Reason for revert: Cause test failure.

Original change's description:
> Always offer transport sequence number header extension for audio
> 
> If the extension is negotiated, it will only be used if
> the field trial WebRTC-Audio-SendSideBwe is enabled.
> This allows simpler experimentation if it should be used or not.
> 
> Bug: webrtc:10309 webrtc:10286
> Change-Id: I797e6f14c06d46189e40f6d09805c2e09afc015b
> Reviewed-on: https://webrtc-review.googlesource.com/c/122542
> Commit-Queue: Per Kjellander <perkj@webrtc.org>
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Reviewed-by: Sebastian Jansson <srte@webrtc.org>
> Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#26689}

TBR=ossu@webrtc.org,sprang@webrtc.org,srte@webrtc.org,perkj@webrtc.org

Change-Id: I1b7d3fa5c282a5bf049ca54695ad16c8278a2698
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:10309 webrtc:10286
Reviewed-on: https://webrtc-review.googlesource.com/c/123182
Reviewed-by: Ying Wang <yinwa@webrtc.org>
Commit-Queue: Ying Wang <yinwa@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26703}
diff --git a/rtc_base/experiments/audio_allocation_settings.cc b/rtc_base/experiments/audio_allocation_settings.cc
index a505357..79c5a0d 100644
--- a/rtc_base/experiments/audio_allocation_settings.cc
+++ b/rtc_base/experiments/audio_allocation_settings.cc
@@ -65,12 +65,16 @@
   return audio_send_side_bwe_;
 }
 
-bool AudioAllocationSettings::ShouldSendTransportSequenceNumber(
+bool AudioAllocationSettings::EnableTransportSequenceNumberExtension() const {
+  // TODO(srte): Update this to be more accurate.
+  return audio_send_side_bwe_ && !allocate_audio_without_feedback_;
+}
+
+bool AudioAllocationSettings::IncludeAudioInFeedback(
     int transport_seq_num_extension_header_id) const {
   if (force_no_audio_feedback_)
     return false;
-  return audio_send_side_bwe_ && !allocate_audio_without_feedback_ &&
-         transport_seq_num_extension_header_id != 0;
+  return transport_seq_num_extension_header_id != 0;
 }
 
 bool AudioAllocationSettings::UpdateAudioTargetBitrate(
diff --git a/rtc_base/experiments/audio_allocation_settings.h b/rtc_base/experiments/audio_allocation_settings.h
index f05b4a3..bcc0f3e 100644
--- a/rtc_base/experiments/audio_allocation_settings.h
+++ b/rtc_base/experiments/audio_allocation_settings.h
@@ -27,13 +27,14 @@
   bool IgnoreSeqNumIdChange() const;
   // Returns true if the bitrate allocation range should be configured.
   bool ConfigureRateAllocationRange() const;
-  // Returns true if sent audio packets should have transport wide sequence
-  // numbers.
+  // Returns true if the transport sequence number extension should be enabled.
+  bool EnableTransportSequenceNumberExtension() const;
+  // Returns true if audio traffic should be included in transport wide feedback
+  // packets.
   // |transport_seq_num_extension_header_id| the extension header id for
   // transport sequence numbers. Set to 0 if not the extension is not
   // configured.
-  bool ShouldSendTransportSequenceNumber(
-      int transport_seq_num_extension_header_id) const;
+  bool IncludeAudioInFeedback(int transport_seq_num_extension_header_id) const;
   // Returns true if target bitrate for audio streams should be updated.
   // |transport_seq_num_extension_header_id| the extension header id for
   // transport sequence numbers. Set to 0 if not the extension is not