Fix audio unit initialization condition in AudioDeviceIOS::UpdateAudioUnit

Author: 小田喜陽彦

sdk/objc/native/src/audio/audio_device_ios.mm

@@ -816,7 +816,7 @@ static void LogDeviceInfo() {
   // be initialized on initialization.
   if (!audio_is_initialized_) return;
 
-  if (!audio_unit_ && !CreateAudioUnit()) {
+  if (can_play_or_record && !audio_unit_ && !CreateAudioUnit()) {
     RTCLog(@"Failed to create audio unit.");
     return;
   }