[behavior][XWALK-2495] Rename media resource file for namespace issue

- Rename eAAC+ to HE-AAC becasue of XWALK-2495
- Delete the eAAC+ media file because of not referenced
Merge pull request #864 from JianfengXu/xujf/2495

[behavior][XWALK-2495] Rename media resource file for namespace issue