[embedding][XWALK-1040] Add new embedding api tests for crosswalk

- Add 27 cases about the unit tests for embedding api.
- Failure analysis:8 cases are failed because the methods of embedding api are not exist.

Impacted tests(designed|approved): new 27, update 0, delete 0
Unit test platform: [Android]
Unit test result summary: pass 87, fail 20, block 4