Add the ass file MIME that the SAF considers

[vvb2060]

Unfortunately, the Android system considers ass files to be audio, so SAF cannot select them.

Additional information:

   Deprecated alias names for this type: N/A
   Magic number(s): N/A 
   File extension(s): .adts or .aac (ADTS), .loas or .ass (LATM/LOAS)
   Macintosh file type code(s): N/A

https://www.iana.org/assignments/media-types/audio/aac

[SeeFlowerX]

yes we need !