Duplicate sounds file names are displayed in notification list

There are few duplicate notification sound files present in
/data/sounds/notifications & data/sounds/notifications/ogg.
- arcturus.ogg
- vega.ogg

Maintain sound files only under /data/sounds/notifications/ogg.

Change-Id: Ibe347ed03d19a1ce4cb13c1bce1e4bbc26cb61be
CRs-fixed: 630101