base: cleanup duplicate alarm sounds

http://jira.omnirom.org/browse/OMNI-762

Alarm_Classic is the same as Cesium (updating meta-data)
Promethium had wrong title meta data

Change-Id: I8096a12d2690691ae5252e1ffc48184f0a2c9510
(cherry picked from commit afd9cf2577c086feea6ee90ef72eb1b816d2e881)