Implement a hamcrest-matcher selector strategy

[dpgraham]

See https://medium.com/google-developers/adapterviews-and-espresso-f4172aa853cf for reference

• AdapterViews don't render all the items at once
• To target a View that isn't on the screen, Espresso has a method onData(<matcher>)
• The matcher is a Hamcrest matcher that matches views
• Currently, we don't use onData we use onView which only finds elements on the page
• We need to figure out if we can use onData to target views using currently supported selectors but I also think we should add a broader 'hamcrest matcher' strategy that lets people put in arbitrary hamcrest selection strategies