[embedding][XWALK-2381] Change loadAppFromManifest mode to sync and improve pack.sh

- Change loadAppFromManifest test method from async mode to sync mode.
- Improve testLoadUrl method by judging title.
- Improve pack.sh to fit different environment versions.

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Android]
Unit test result summary: pass 84, fail 18, block 4