[Android] Add new Crosswalk Sample code

Add the sample code for demonstrate the usage of some Crosswalk Embedding API, covering ones:
1. XWalkView.getAPIVersion()
2. XWalkView.getXWalkVersion()
3. XWaklNavigationItem.getUrl()
4. XWaklNavigationItem.getOriginalUrl()
5. XWaklNavigationItem.getTitle()

BUG=XWALK-1230