[wrt]Update xwalk-launcher to open_app

[Detailed commit message (if have)]
Impacted TCs num(approved):New 0,Update 5,Delete 0
UT result: Pass 5, Fail 0, Block 0
Merge pull request #1227 from linshen/shenlin/update-xwalk-open_app

[wrt]Update xwalk-launcher to open_app