cts: add testMpeg4_adaptiveDrc

Also add test clip, which is generated with ffmpeg-2.3.1:
./ffmpeg -i video_1280x720_mp4_h264_1000kbps_25fps_aac_stereo_128kbps_44100hz.mp4 -strict -2 -codec:v mpeg4 -b:v 1000k -b:a 128k -ar 44100 video_1280x720_mp4_mpeg4_1000kbps_25fps_aac_stereo_128kbps_44100hz.mp4

Bug: 17326758
Change-Id: I42e38ede8ce8e6d37fda7a20713ee605c40462e9
2 files changed