PulseAudio: fix QAudioOutput state after resume().

In push mode, the state must be IdleState after resume(), and only
change to ActiveState once it receives some data.

Change-Id: I8caff011f517e91629abf45af51580f24136bcea
Task-number: QTBUG-50390
Reviewed-by: Pasi Petäjäjärvi <pasi.petajajarvi@theqtcompany.com>

src/plugins/pulseaudio/qaudiooutput_pulse.cpp

@@ -555,7 +555,7 @@ void QPulseAudioOutput::resume()
 
         m_tickTimer->start(m_periodTime);
 
-        setState(QAudio::ActiveState);
+        setState(m_pullMode ? QAudio::ActiveState : QAudio::IdleState);
         setError(QAudio::NoError);
     }
 }