Add Android Example

This is an example based on [dagger's activity graph](https://github.com/square/dagger/tree/master/examples/android-activity-graphs) and [tape's example](https://github.com/square/tape/tree/master/tape-sample) which does a simple zone list.  Credentials are configured via the preferences screen, which reads the parameter names from our `Provider` interface.

Remote denominator providers won't work on android until https://github.com/Netflix/denominator/pull/159 (which rids cglib dep).  However, we can start playing around with the MockProvider in the mean time.

This would be a good basis for a [cloud prize](https://github.com/Netflix/Cloud-Prize/wiki) entry for an android app.  We've discussed the name [denomadroid](https://groups.google.com/forum/?hl=en&fromgroups#!searchin/denominator-dev/denomadroid/denominator-dev/4Jx2HkN-pVU/loPCjtmVfCkJ) before, but so far, no-one has started it.