[ivi-tct][webapi][xwalk-3179] Revise timeout to 5000 from 500

- Change timeout to 5000, too short timeout will make test fail

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [IVI]
Unit test result summary: pass 1, fail 0, block 0
Merge pull request #1527 from haoxli/tct/webapi/xwalk-3179-2

[ivi-tct][webapi][xwalk-3179] Revise timeout to 5000 from 500
[ivi-tct][webapi][XWALK-3212] Remove this w3c test including idlharness

- Remove w3c mediastreamtrack-init-manual.html, since this is idlharness test
Merge pull request #1529 from xinliux/gumallow/XWALK-3212

[ivi-tct][webapi][XWALK-3212] Remove this w3c test including idlharness