[sample-wrt][xwalk-2871] Update one case for demo-express

Impacted TCs num(approved): New 0, Update 1, Delete 0
Unit test Platform: Android
Android test result summary: Pass 1, Fail 0, Block 0
Merge pull request #31 from wanghongjuan/wrt/xwalk-2871

[sample-wrt][xwalk-2871] Update one case for demo-express