[ivi-tct][XWALK-3204] Delete the duplicated case ID

- Delete the duplicated case ID background-002.
[ivi-tct] Format tests.xml and tests.full.xml

- Format tests.xml by "xmllint --format tests.xml"
- Format tests.full.xml by "xmllint --format tests.full.xml"
Merge pull request #1522 from chenxix/webapi/modify-background-ivi-tct

[ivi-tct][XWALK-3204] Delete the duplicated case ID