Adds audio session status to logs for each valid audio route change on iOS

webrtc/modules/audio_device/ios/audio_device_ios.mm

Index: webrtc/modules/audio_device/ios/audio_device_ios.mm
diff --git a/webrtc/modules/audio_device/ios/audio_device_ios.mm b/webrtc/modules/audio_device/ios/audio_device_ios.mm
index 8f562a7b1429d1123320ce2af8c5187586e168ea..dc6cdcb8e4bd5040e6f4e3d24877c8ea7c08b52d 100644
--- a/webrtc/modules/audio_device/ios/audio_device_ios.mm
+++ b/webrtc/modules/audio_device/ios/audio_device_ios.mm
@@ -491,6 +491,7 @@ void AudioDeviceIOS::HandleValidRouteChange() {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
 
   RTCAudioSession* session = [RTCAudioSession sharedInstance];
+  RTCLog(@"%@", session);
   HandleSampleRateChange(session.sampleRate);
 }