Revert "Turn on WebRTC-TaskQueuePacer by defualt."

This reverts commit b251145e38fdd08fe7320b0ddb3ca0f698473fa5.

Reason for revert: Downstream issue

Original change's description:
> Turn on WebRTC-TaskQueuePacer by defualt.
>
> Bug: webrtc:10809
> Change-Id: If58ae3d9debc69ee68e6aeb6cecf010e60f6426f
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/233580
> Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
> Commit-Queue: Erik Språng <sprang@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#35145}

TBR=sprang@webrtc.org,crodbro@webrtc.org,webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I3a8db6fc2376ccc528f1e2fa6acc08ce05afebbf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:10809
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/234340
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35150}
diff --git a/call/rtp_transport_controller_send.cc b/call/rtp_transport_controller_send.cc
index 9d27b33..f7b6b11 100644
--- a/call/rtp_transport_controller_send.cc
+++ b/call/rtp_transport_controller_send.cc
@@ -89,7 +89,7 @@
       bitrate_configurator_(bitrate_config),
       pacer_started_(false),
       process_thread_(std::move(process_thread)),
-      use_task_queue_pacer_(!IsDisabled(trials, "WebRTC-TaskQueuePacer")),
+      use_task_queue_pacer_(IsEnabled(trials, "WebRTC-TaskQueuePacer")),
       process_thread_pacer_(use_task_queue_pacer_
                                 ? nullptr
                                 : new PacedSender(clock,