Revert "Implement RtpParameters.transaction_id for PC RtpSenderInterface"

This reverts commit 5faf36ef3c582350fba5ef97a3549e440d81a283.

Reason for revert: fast/peerconnection/RTCRtpSender-setParameters.html
 failing in webrtc roll, probably this CL? https://chromium-review.googlesource.com/c/chromium/src/+/1045889.

Original change's description:
> Implement RtpParameters.transaction_id for PC RtpSenderInterface
> 
> The transaction_id field should be refreshed for every getParameters()
> call and checked at each setParameters() call.
> This also checks that getParameters() was ever called to return a proper
> error code.
> 
> Bug: webrtc:7580
> Change-Id: I6c6fe289542e486fc422cdc61577982b0529d4c1
> Reviewed-on: https://webrtc-review.googlesource.com/70820
> Commit-Queue: Florent Castelli <orphis@webrtc.org>
> Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
> Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
> Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
> Reviewed-by: Steve Anton <steveanton@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#23120}

TBR=steveanton@webrtc.org,deadbeef@webrtc.org,sakal@webrtc.org,kthelgason@webrtc.org,orphis@webrtc.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: webrtc:7580
Change-Id: I86da108227f8fc8d235bb2e9559377c800595b8c
Reviewed-on: https://webrtc-review.googlesource.com/74740
Reviewed-by: Max Morin <maxmorin@webrtc.org>
Commit-Queue: Max Morin <maxmorin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23134}
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCRtpParameters.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCRtpParameters.mm
index d18eba6..5e79106 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCRtpParameters.mm
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCRtpParameters.mm
@@ -10,13 +10,11 @@
 
 #import "RTCRtpParameters+Private.h"
 
-#import "NSString+StdString.h"
 #import "RTCRtpCodecParameters+Private.h"
 #import "RTCRtpEncodingParameters+Private.h"
 
 @implementation RTCRtpParameters
 
-@synthesize transactionId = _transactionId;
 @synthesize encodings = _encodings;
 @synthesize codecs = _codecs;
 
@@ -27,7 +25,6 @@
 - (instancetype)initWithNativeParameters:
     (const webrtc::RtpParameters &)nativeParameters {
   if (self = [self init]) {
-    _transactionId = [NSString stringForStdString:nativeParameters.transaction_id];
     NSMutableArray *encodings = [[NSMutableArray alloc] init];
     for (const auto &encoding : nativeParameters.encodings) {
       [encodings addObject:[[RTCRtpEncodingParameters alloc]
@@ -46,8 +43,7 @@
 }
 
 - (webrtc::RtpParameters)nativeParameters {
-  webrtc::RtpParameters parameters;
-  parameters.transaction_id = [NSString stdStringForString:_transactionId];
+    webrtc::RtpParameters parameters;
   for (RTCRtpEncodingParameters *encoding in _encodings) {
     parameters.encodings.push_back(encoding.nativeParameters);
   }