This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Just played with Eclipse: looks like the IDE removes the method from the list of methods to insert/override if you have already inserted/overriden it. So since your Activity already has the boolean onCreateOptionsMenu(Menu) method, that method is removed from the list.