[webapi] Add 8 TCs to webapi-dlna-xwalk-tests

 Impacted TCs num: New 8, Update 0, Delete 0
 Unit test Platform: IVI
 Tizen test result summary: Pass 0, Fail 8, Block 0
 Android test result summary: Pass 0, Fail 8, Block 0

Fail reason:
  The crosswalk does not support the mediaServer attribute.