[webapi][xwalk-2411] Remove 1 test for battery level in Tizen SystemInfo

- Platform specific, IVI have no an on-board battery, this case is not applicable, change it to 'designed' in tests.full.xml, remove it from tests.xml
Merge pull request #1243 from haoxli/webapi/xwalk-2411

[webapi][xwalk-2411] Remove 1 test for battery level in Tizen SystemInfo