[MT.D] Fixes tvOS library and sample build

[dalexsoto]

The tvOS build of both the sample and library were broken.

• The resource arrow.png is no longer used and was removed by https://github.com/migueldeicaza/MonoTouch.Dialog/commit/338abfe687d2461536272017ca439b443db5c2ad but only for the iOS project.
• Adds some boilerplate information to Sample/Info-tvOS.plist so the sample runs out of the box.
• UIRefreshControl is not available in tvOS.