core layer: do not destroy stream when in use

When we stop playback stream we should check current audio category.
If it is AVAudioSessionCategoryPlayAndRecord it is means we also have
capture stream running and we should not destroy it.

Change-Id: I4cc0f2ddcd8b26840f4b2968a890c4803c187448

src/media/audio/coreaudio/ios/corelayer.mm

@@ -145,7 +145,6 @@ CoreLayer::initAudioLayerIO(AudioDeviceType stream)
         default:
             break;
     }
-
     setupOutputBus();
     if (setUpInput) {
         setupInputBus();
@@ -327,9 +326,9 @@ CoreLayer::startStream(AudioDeviceType stream)
 {
     dispatch_async(audioConfigurationQueueIOS(), ^{
         JAMI_DBG("iOS CoreLayer - Start Stream");
-        auto currentCategoty =  [[AVAudioSession sharedInstance] category];
+        auto currentCategory =  [[AVAudioSession sharedInstance] category];
 
-        bool updateStream = currentCategoty == AVAudioSessionCategoryPlayback && (stream == AudioDeviceType::CAPTURE || stream == AudioDeviceType::ALL);
+        bool updateStream = currentCategory == AVAudioSessionCategoryPlayback && (stream == AudioDeviceType::CAPTURE || stream == AudioDeviceType::ALL);
         if (status_ == Status::Started) {
             if (updateStream)
                 destroyAudioLayer();
@@ -349,6 +348,7 @@ CoreLayer::startStream(AudioDeviceType stream)
 void
 CoreLayer::destroyAudioLayer()
 {
+    JAMI_DBG("iOS CoreLayer - destroy Audio layer");
     AudioOutputUnitStop(ioUnit_);
     AudioUnitUninitialize(ioUnit_);
     AudioComponentInstanceDispose(ioUnit_);
@@ -360,7 +360,9 @@ CoreLayer::stopStream(AudioDeviceType stream)
 {
     dispatch_async(audioConfigurationQueueIOS(), ^{
         JAMI_DBG("iOS CoreLayer - Stop Stream");
-        if (status_ != Status::Started)
+        auto currentCategory =  [[AVAudioSession sharedInstance] category];
+        bool keepCurrentStream = currentCategory == AVAudioSessionCategoryPlayAndRecord && (stream == AudioDeviceType::PLAYBACK);
+        if (status_ != Status::Started || keepCurrentStream)
             return;
         status_ = Status::Idle;
         destroyAudioLayer();