Modified the non-large layout to have a fragment element.

  Effected Files:
    FragmentHierarchicalNavigation\Activity1.cs
    FragmentHierarchicalNavigation\FragmentNavEx.csproj
    FragmentHierarchicalNavigation\Resources\Layout\Main.axml
    FragmentHierarchicalNavigation\Resources\Resource.Designer.cs
    FragmentHierarchicalNavigation\Resources\Values\Strings.xml