[Android] Clean up the function CopyAsset in DolphinEmulator.java.

[streamtype].flush() is called when [streamtype].close() is called.

No need to null the references either after calling close(), the garbage collection will take care of it.

Source/Android/src/org/dolphinemu/dolphinemu/DolphinEmulator.java

@@ -33,10 +33,7 @@ public class DolphinEmulator<MainActivity> extends Activity
           out = new FileOutputStream(output);
           copyFile(in, out);
           in.close();
-          in = null;
-          out.flush();
           out.close();
-          out = null;
         } catch(IOException e) {
             Log.e("DolphinEmulator", "Failed to copy asset file: " + asset, e);
         }       
@@ -78,7 +75,6 @@ public class DolphinEmulator<MainActivity> extends Activity
 		super.onCreate(savedInstanceState);
 		if (savedInstanceState == null)
 		{
-
 			Intent ListIntent = new Intent(this, GameListActivity.class);
 			startActivityForResult(ListIntent, 1);