[abat] Update abat tests

- Removed 5 BAT tests: File API: Directories and System (Partial), File API: Writer (Partial), Shadow DOM, Navigation Timing, Timing control for script-based animations
- Updated 3 BAT tests: File API, WebGL API, WebRTC
- Fail reason: WebRTC RTCPeerConnect is not implemented
  BUG=XWALK-2239

Impacted tests(approved): new 0, update 3, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 2, fail 1, block 0
Merge pull request #767 from haoxli/haoxli/abat/update-tests

[abat] Update abat tests