Update AudioPlayerModule.java

Fix error in Android <= 6 due to attempting to pause the player when it is not already playing.

Author: Shane

android/src/main/java/com/reactnativecommunity/rctaudiotoolkit/AudioPlayerModule.java

@@ -373,7 +373,7 @@ public void set(Integer playerId, ReadableMap options, Callback callback) {
 
             player.setPlaybackParams(params);
 
-            if (needToPauseAfterSet) {
+            if (needToPauseAfterSet && player.isPlaying()) {
                 player.pause();
             }
         }