[usecase-webapi] Improve WebSpeech usecase

- Adjust the case with screen view
- Failure analysis: Could not connect to speech recognition service

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 0, fail 1, block 0
Merge pull request #591 from yunxliu/yunxliu/misc/webSpeech

[usecase-webapi] Improve WebSpeech usecase