[xwalkdriver] Add tests.xml for xwalkdriver tests

- Add tests.xml for testskit-lite
- Improve Android test steps
- Pack APK zip
Add WebAudio crashing sample
Merge pull request #515 from platogo/webaudio

WebAudio crashing sample
Merge pull request #479 from haoxli/haoxli/webdriver/tests.xml

[xwalkdriver] Add tests.xml for xwalkdriver tests