Current behavior is to retrieve alarm by id and conduct operations on the
object. If the tenant doesn't own the alarm or isn't admin, the user will
receive the message: 'NoneType' object has no attribute 'to_dict'
Above message doesn't provide any useful diagnostic information and indicates a
programming error since an unexpected None-type is encountered and not handled.
This change verifies the alarm is found before using the object. If alarm not
found it prints the same message for a not found Alarm as other PUT operations
like alarm-state-set: Alarm not found: <alarm_id>.
This message is more useful for diagnosis and gets rid of the uncaught
None-type error.
Change-Id: I66abcd4498b24ac7cadcf29fe3ced3fcda08458c
Closes-Bug: #1348387
8a01731d4e