Change aggregation window of aecDivergentFilterFraction to 1 second.

BUG=

Review-Url: https://codereview.webrtc.org/1942183002
Cr-Commit-Position: refs/heads/master@{#12617}

webrtc/modules/audio_processing/include/audio_processing.h

@@ -685,7 +685,7 @@ class EchoCancellation {
     // (Pre non-linear processing suppression) A_NLP = 10log_10(P_echo / P_a)
     AudioProcessing::Statistic a_nlp;
 
-    // Fraction of time that the AEC linear filter is divergent, in a 0.5-second
+    // Fraction of time that the AEC linear filter is divergent, in a 1-second
     // non-overlapped aggregation window.
     float divergent_filter_fraction;
   };