[usercase-wrt] update mutiuser testcase to designed

[Detailed commit message (if have)]
Impacted TCs num(designed): New 0, update 0, deleted 0
Unit test platform: [tizen]
Unit test result summary: only update tests.xml
Merge pull request #890 from linshen/shenlin/wrt-usecase-move-multiuser

[usercase-wrt] update mutiuser testcase to designed
[wrt][XWALK-1649]Add multiuser tcs for wrt-commandlinemanu-tizen-tests

[Detailed commit message (if have)]
Impacted TCs num(designed): New 6, update 0, deleted 0
Unit test platform: [tizen]
Unit test result summary: Pass 6, fail 0, block 0
Merge pull request #878 from linshen/shenlin/wrt/multiuser-xwalk1649

[wrt][XWALK-1649]Add multiuser tcs for wrt-commandlinemanu-tizen-tests