Add a comment about game list color

Source/Android/src/org/dolphinemu/dolphinemu/gamelist/GameListAdapter.java

@@ -70,6 +70,7 @@ public final class GameListAdapter extends ArrayAdapter<GameListItem>
 			}
 		}
 
+		// Make every other game in the list grey
 		if (position % 2 == 1)
 			convertView.setBackgroundColor(0xFFE3E3E3);