I think you're focusing too much on the underlying technology, Dalvik is ultimately little more than a layer of indirection, that could easily disappear deeply

I think you're focusing too much on the underlying technology, Dalvik is ultimately little more than a layer of indirection, that could easily disappear deeply beneath the covers of a 22nd century OS, hidden by a simple click of a 'Build' button in an IDE, much like Win32 did. Similarly, Contacts was only used as an example, as it is prominent and simple to understand. The main reference made there was to the data the Contacts UI represents, which ultimately backs on to some class library that ultimately is controlled by the platform (as I understand it).