Add validate alarm_actions schema in alarm API

Currently, alarm API does not validate schema in alarm_actions.
When invalid schema is specified, error occurs later in alarm notifier.
Schema should be validated in advance in API.

Change-Id: I3b28cfe36c460daead2945ba3577fbc1274f9d91
Closes-bug: #1342673
Merge "Add validate alarm_actions schema in alarm API"