[webapi] Add 1 P2 test for Media Render API
Impacted tests(approved): new 1, update 0, delete 0
Unit test platform: [IVI]
Unit test result summary: pass 1, fail 0, block 0
Merge pull request #1355 from kangxu/kangxu/webapi/webapi-mediarenderer-tizen-tests/fixGap

[webapi] Add 1 P2 test for Media Render API