message: AgcManagerDirect: improve AgcMinMicLevelExperimentEnabled50 test
  Also test the field trial with valid parameter and non-empty suffix.
  Cr-Commit-Position: refs/heads/main@{#36031}
diff: @@ -128,13 +128,15 @@ void CallPreProcessAudioBuffer(int num_calls,
  }
  }
  -std::string GetAgcMinMicLevelExperimentFieldTrial(int enabled_value) {
  +std::string GetAgcMinMicLevelExperimentFieldTrial(
  + int enabled_value,
  + const std::string& suffix = "") {
  RTC_DCHECK_GE(enabled_value, 0);
  RTC_DCHECK_LE(enabled_value, 255);
  char field_trial_buffer[64];
  rtc::SimpleStringBuilder builder(field_trial_buffer);
  builder << "WebRTC-Audio-AgcMinMicLevelExperiment/Enabled-" << enabled_value
  - << "/";
  + << suffix << "/";
  return builder.str();
  }
  @@ -883,14 +885,17 @@ TEST(AgcManagerDirectStandaloneTest, AgcMinMicLevelExperiment) {
  }
  TEST(AgcManagerDirectStandaloneTest, AgcMinMicLevelExperimentDisabled) {
  + for (const std::string& field_trial_suffix : {"", "_20220210"}) {
  test::ScopedFieldTrials field_trial(
  - "WebRTC-Audio-AgcMinMicLevelExperiment/Disabled/");
  + "WebRTC-Audio-AgcMinMicLevelExperiment/Disabled" + field_trial_suffix +
  + "/");
  std::unique_ptr<AgcManagerDirect> manager =
  CreateAgcManagerDirect(kInitialVolume, kClippedLevelStep,
  kClippedRatioThreshold, kClippedWaitFrames);
  EXPECT_EQ(manager->channel_agcs_[0]->min_mic_level(), kMinMicLevel);
  EXPECT_EQ(manager->channel_agcs_[0]->startup_min_level(), kInitialVolume);
  }
  +}
  // Checks that a field-trial parameter outside of the valid range [0,255] is
  // ignored.
  @@ -921,14 +926,17 @@ TEST(AgcManagerDirectStandaloneTest, AgcMinMicLevelExperimentOutOfRangeBelow) {
  // changed.
  TEST(AgcManagerDirectStandaloneTest, AgcMinMicLevelExperimentEnabled50) {
  constexpr int kMinMicLevelOverride = 50;
  - test::ScopedFieldTrials field_trial(
  - GetAgcMinMicLevelExperimentFieldTrial(kMinMicLevelOverride));
  + for (const std::string& field_trial_suffix : {"", "_20220210"}) {
  + SCOPED_TRACE(field_trial_suffix);
  + test::ScopedFieldTrials field_trial(GetAgcMinMicLevelExperimentFieldTrial(
  + kMinMicLevelOverride, field_trial_suffix));
  std::unique_ptr<AgcManagerDirect> manager =
  CreateAgcManagerDirect(kInitialVolume, kClippedLevelStep,
  kClippedRatioThreshold, kClippedWaitFrames);
  EXPECT_EQ(manager->channel_agcs_[0]->min_mic_level(), kMinMicLevelOverride);
  EXPECT_EQ(manager->channel_agcs_[0]->startup_min_level(), kInitialVolume);
  }
  +}
  // Checks that, when the "WebRTC-Audio-AgcMinMicLevelExperiment" field trial is
  // specified with a valid value, the mic level never gets lowered beyond the
  