Adding comment regarding the disabling the flaky test VolumeTest.ManualRequiresMicrophoneCanSetMicr…

webrtc/voice_engine/test/auto_test/standard/volume_test.cc

Index: webrtc/voice_engine/test/auto_test/standard/volume_test.cc
diff --git a/webrtc/voice_engine/test/auto_test/standard/volume_test.cc b/webrtc/voice_engine/test/auto_test/standard/volume_test.cc
index c9b5c5226e4603b9b9812982a46cc3f6c3bbe7cc..fa0c0eab6443c04a4afe6acef9f7809d9b04a166 100644
--- a/webrtc/voice_engine/test/auto_test/standard/volume_test.cc
+++ b/webrtc/voice_engine/test/auto_test/standard/volume_test.cc
@@ -173,6 +173,7 @@ TEST_F(VolumeTest, DefaultMicrophoneVolumeIsAtMost255) {
   }
 }
 
+// The test below is disabled due to issue webrtc:6206.
 TEST_F(VolumeTest, DISABLED_ManualRequiresMicrophoneCanSetMicrophoneVolumeWithAgcOff) {
   SwitchToManualMicrophone();
   EXPECT_EQ(0, voe_apm_->SetAgcStatus(false));