[embedding][XWALK-895] Add new embedding api tests for xwalk


- Add 80 cases about the unit tests for embedding api.
- Failure analysis:8 cases are failed because the methods of embedding api are not exist.
Others are failed or blocked because the methods of embedding api do not support.

Impacted tests(designed|approved): new 80, update 0, delete 0
Unit test platform: [Android]
Unit test result summary: pass 68, fail 12, block 4