Add SimpleMenuXXX implementation for the Gingerbread platform.

1. Add a SimpleMenuInflator to parse the res/menu/xxx.xml files.
2. Add minimal code to show the menu.

**NOTE**
This change is going to be replaced by the ActionBar compat library
when it gets ready and integrated. The purpose of this change is making
Gallery/Camera run on GB.

Change-Id: Ia7d402c82a6da1b9558ebbd103e161d2471b34dd