[usecase-wrt] modify wrt-usecase-tizen-tests

[Detailed commit message]
Unit test platform: [tizen]
Unit test result summary: pack to wgt/xpk, all tcs is showing normally
Merge pull request #533 from linshen/modify-wrt-usecase-tizen-test

[usecase-wrt] modify tizen usecase for wrt-usecase-tizen-tests