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.
Working on amlogic, I had to change to the following to get "Tear of Steel" (TearsOfSteelFull12min_1080p_24fps_27qp_1474kbps_GPSNR_42.29_HM11.mkv) working:

```
        // TODO: from Amlogic
        /* It seems the extradata is encoded as hvcC format.
         * Temporarily, we support configurationVersion==0 until 14496-15 3rd
         * is finalized. When finalized, configurationVersion will be 1 and we
         * can recognize hvcC by checking if extradata[0]==1 or not. */

        if (in_extradata[0] || in_extradata[1] || in_extradata[2] > 1)
        {
```


Does that make sense?