Remove unused field trial string kRTCFieldTrialAudioForceNoTWCCKey

Bug: webrtc:8243
Change-Id: I9c24999e44a749669208e19574d1251dcbd22d77
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/284941
Auto-Submit: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38727}
diff --git a/sdk/objc/api/peerconnection/RTCFieldTrials.h b/sdk/objc/api/peerconnection/RTCFieldTrials.h
index 1f290d8..a42a961 100644
--- a/sdk/objc/api/peerconnection/RTCFieldTrials.h
+++ b/sdk/objc/api/peerconnection/RTCFieldTrials.h
@@ -13,7 +13,6 @@
 #import "RTCMacros.h"
 
 /** The only valid value for the following if set is kRTCFieldTrialEnabledValue. */
-RTC_EXTERN NSString * const kRTCFieldTrialAudioForceNoTWCCKey;
 RTC_EXTERN NSString * const kRTCFieldTrialAudioForceABWENoTWCCKey;
 RTC_EXTERN NSString * const kRTCFieldTrialSendSideBweWithOverheadKey;
 RTC_EXTERN NSString * const kRTCFieldTrialFlexFec03AdvertisedKey;
diff --git a/sdk/objc/api/peerconnection/RTCFieldTrials.mm b/sdk/objc/api/peerconnection/RTCFieldTrials.mm
index 852aeee..e16d39e 100644
--- a/sdk/objc/api/peerconnection/RTCFieldTrials.mm
+++ b/sdk/objc/api/peerconnection/RTCFieldTrials.mm
@@ -16,7 +16,6 @@
 
 #include "system_wrappers/include/field_trial.h"
 
-NSString * const kRTCFieldTrialAudioForceNoTWCCKey = @"WebRTC-Audio-ForceNoTWCC";
 NSString * const kRTCFieldTrialAudioForceABWENoTWCCKey = @"WebRTC-Audio-ABWENoTWCC";
 NSString * const kRTCFieldTrialSendSideBweWithOverheadKey = @"WebRTC-SendSideBwe-WithOverhead";
 NSString * const kRTCFieldTrialFlexFec03AdvertisedKey = @"WebRTC-FlexFEC-03-Advertised";