Added Activity and Layout for ordering Pizza

Created and Added PizzaOrderingActivity.java
Created and Added pizza_ordering_activity_layout.xml
Edited Strings.xml ( Added strings for pizza layout for
internationalization )
Added Order Pizza button view object to NavigationActivity.java
Set necessary listener and intent for navigating to
PizzaOrderingActivity.java
Edited AndroidManifest.xml ( Added declaration for PizzaOrderingActivity
and set parent class )
Edited navigation_activity_layout.xml (Added necessary xml for the new
Pizza Order button)