[usecase-webapi] Improve SystemInfo usecase

- Adjust the case with screen view

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 1, fail 0, block 0
Merge pull request #637 from yunxliu/yunxliu/misc/systemInfo

[usecase-webapi] Improve SystemInfo usecase