AGC1: min mic level override always applied

When the minimum mic level is overridden via the field trial named
WebRTC-Audio-AgcMinMicLevelExperiment, AGC1 can still lower the gain
beyond the minimum value (namely, when clipping is observed).

This CL changes the behavior of the field trial. When specified, the
override always applies and therefore the mic level is guaranteed to
never become lower than what the field trial specifies.

Tested: RTC call in Chromium with and without --force-fieldtrials="
WebRTC-Audio-AgcMinMicLevelExperiment/Enabled-255"

Bug: chromium:1275566
Change-Id: I42ff45add54c11084f5ca6a2b95887c627c3c3aa
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/250141
Reviewed-by: Hanna Silen <silen@webrtc.org>
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35914}
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 45e0b6a..6282633 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -788,8 +788,7 @@
  public:
   // sample_rate_hz: The sampling rate of the stream.
   // num_channels: The number of audio channels in the stream.
-  StreamConfig(int sample_rate_hz = 0,
-               size_t num_channels = 0)
+  StreamConfig(int sample_rate_hz = 0, size_t num_channels = 0)
       : sample_rate_hz_(sample_rate_hz),
         num_channels_(num_channels),
         num_frames_(calculate_frames(sample_rate_hz)) {}