title: Set volume for notification without set the ringtone volume
body: <p>I want to manage the volume of all system notifications.</p>
  
  <p>If I use this the call volume is changed too.</p>
  
  <pre><code>    audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
      audioManager.setStreamVolume(AudioManager.STREAM_NOTIFICATION, 0, 0);
  </code></pre>
  
  <p>How can I change only the notifications volume?</p>
  
  <p>Thanks</p>