Do not display background shape in fullscreen notification if there’s nothing in it

So nothing cover a photo when using AirPlay photo sharing

(cherry picked from commit 92f02ac76c7011420b3e2981210826f651dc65da)
Improve AirPlay device visibility in iOS 7

For some reasons, my iPhone doesn’t always show mythtv as an AirPlay device, and more often than not only show it as an audio device.
After playing a lot with the various bonjour advertising data, what I can gather is:
- If AirPlay video reports a version >= 120.x; the iPhone will attempt to use FairPlay DRM no matter what RAOP reports (even if it reports no support for encryption)
- If there’s a mismatch of version between AirPlay video and RAOP: the iPhone 5 won’t show the video service
- If reporting a version < 110 in AirPlay video, then photo sharing doesn’t reliably work
- If bit 10 in features bitmask is cleared, it doesn’t reliably show up
So I set the AirPlay video version to 115.3 (made up value) that allows photo sharing, and RAOP also to 115.3 and it all seem to work nicely now

(cherry picked from commit 7e2f21c8a3614fe059abed3801aafd6dbc1ed07a)