The important changes are as follows.
  The fragment views were replaced with a FrameLayout.
  The DisplayHomeUpEnabled was uncommented.

This commit fixes the following issues.
https://github.com/asparkman/FragmentHierarchicalNavExample/issues/1
https://github.com/asparkman/FragmentHierarchicalNavExample/issues/2
https://github.com/asparkman/FragmentHierarchicalNavExample/issues/3