[wrt] Fix XWALK-1636/1645 to update  test step

Impacted TCs num(approved): New 0, update 3, deleted 0
Unit test platform: [tizen]
Unit test result summary: Pass 3   , Fail  0, Blocked  0

xwalk-1636 fixed: update the test site 
xwalk-1645 fixed:  update the install out description