add HEVC 4K LIVE DASH DRM test case

4K + HEVC + live + DRM may raise unique issues not raised by our existing streams. We should consider whether it would be helpful to add such a stream to the reference app.  It should be noted that live streams are expected to have significantly higher bandwidth than on-demand, potentially 30-35 MBit/sec. A VOD stream to be used with livesim for such a test should be encoded at the higher bitrate.