integrate media stress test : MediaPlay and MediaRecord only
MediaPlay test changed to use assets/video directory
due to the limitation of 10 min time-out, video play test is separated
to run one clip per each test case. MediaStressTestRunner simply puts multile
MediaPlayerStressTest cases, and each invokation will play different clips.

Change-Id: I0501d1e3adf69a14d780522d7de7b2596468e407
26 files changed