Camera2: various RecordingTest update

1. The duration from MediaPlayer might be longer due to audio track.
   Change it to only check for video track duration
2. Split basic recording test into two. One test resolutions from
   high to low. The other test video frame rate from low to high.
3. Mark two known failing test
4. Also clean up some duplicated code in RobustnessTest.

Bug: 18705837
Bug: 18689511
Change-Id: I855129cf2d2939c783082dccedee56ef88252a16