Android StageFright and MediaCodec HEVC hw accel

Adds support for HW HEVC decoding on Android

StageFright decoding works for me on an RK3288 based Android player.

MediaCodec fails with an IllegalStateException during MediaCodec::configure.  I have not been able to track down the root cause of this.  It could just be a problem with MediaCodec on my platform, but any pointers for debugging would be appreciated.