- ANDROID audio renderer : added a state check on the MediaPlayer to prenvent it to throw errors

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9437 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/android/com/jme3/audio/android/AndroidAudioRenderer.java

@@ -436,7 +436,9 @@ public class AndroidAudioRenderer implements AudioRenderer,
         if (soundPool != null) {
             soundPool.autoPause();
             for (MediaPlayer mp : musicPlaying.values()) {
-                mp.pause();
+                if(mp.isPlaying()){
+                    mp.pause();
+                }
             }
         }
     }