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

- This is the framework of unit tests for embedding api, use loadUrlSync.

Impated TCs num:New 0, Update 4, Delete 0

Unit test platform: android

Android Test result summary:pass 3,Fail 1,Blocked 0
Merge pull request #312 from zhuyongyong/yongzhu/embaddingAPI

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