asterisk-sounds-extra doesn't know AST_DATA_DIR

[Thiago Martins]

Hi VoIP Maintainers,

 I see that asterisk package is following the FHS via patch
30_ast-data-dir.dpatch, but asterisk-sounds-extra doesn't know
AST_DATA_DIR of asterisk package and it is installing its stuff
under /var/lib/asterisk/sounds and not under /usr/share/asterisk/sounds.

 I'm thinking this is an error... or not?!

Thanks!
Thiago