[webapi] Update 48 designed cases to approved for webaudio

- Modify tests.full.xml and tests.xml

Impacted tests(approved): new 48, update 0, delete 0
Unit test platform: [IVI] crosswalk-10.38.222, t-e-c 0.107
Unit test result summary: pass 0, fail 48, block 0
Merge pull request #1238 from xinliux/webaudio-designed

[webapi] Update 48 designed cases to approved for webaudio