Remove unused method.

Author: dbrant

app/src/main/java/com/dmitrybrant/modelviewer/MainActivity.java

@@ -109,11 +109,6 @@ public boolean onCreateOptionsMenu(Menu menu) {
         return super.onCreateOptionsMenu(menu);
     }
 
-    @Override
-    public boolean onPrepareOptionsMenu(Menu menu) {
-        return super.onPrepareOptionsMenu(menu);
-    }
-
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {