Remove expired WebRTC-Aec3DelayEstimatorDetectPreEcho

Bug: webrtc:14205
Change-Id: Ib817b043d9368ba003b2b40a7315da845910c2f2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/345481
Reviewed-by: Lionel Koenig GĂ©las <lionelk@google.com>
Commit-Queue: Emil Lundmark <lndmrk@webrtc.org>
Reviewed-by: Lionel Koenig <lionelk@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42039}
diff --git a/experiments/field_trials.py b/experiments/field_trials.py
index 3e65411..0bef7ef 100755
--- a/experiments/field_trials.py
+++ b/experiments/field_trials.py
@@ -42,9 +42,6 @@
 # registered in the container below.
 ACTIVE_FIELD_TRIALS: FrozenSet[FieldTrial] = frozenset([
     # keep-sorted start
-    FieldTrial('WebRTC-Aec3DelayEstimatorDetectPreEcho',
-               'webrtc:14205',
-               date(2024, 4, 1)),
     FieldTrial('WebRTC-Audio-GainController2',
                'webrtc:7494',
                date(2024, 4, 1)),
diff --git a/modules/audio_processing/aec3/echo_canceller3.cc b/modules/audio_processing/aec3/echo_canceller3.cc
index e8e2175..fcd9757 100644
--- a/modules/audio_processing/aec3/echo_canceller3.cc
+++ b/modules/audio_processing/aec3/echo_canceller3.cc
@@ -378,14 +378,6 @@
         false;
   }
 
-  if (field_trial::IsEnabled("WebRTC-Aec3DelayEstimatorDetectPreEcho")) {
-    adjusted_cfg.delay.detect_pre_echo = true;
-  }
-
-  if (field_trial::IsDisabled("WebRTC-Aec3DelayEstimatorDetectPreEcho")) {
-    adjusted_cfg.delay.detect_pre_echo = false;
-  }
-
   if (field_trial::IsEnabled("WebRTC-Aec3SensitiveDominantNearendActivation")) {
     adjusted_cfg.suppressor.dominant_nearend_detection.enr_threshold = 0.5f;
   } else if (field_trial::IsEnabled(