Change log for CISCO_UNITY_CONNECTION

Date Changes
2025-05-15 - Added grok patterns to support a new format of syslog logs.
- Added new date patterns to parse "event.idm.read_only_udm.metadata.event_timestamp" UDM field.
- Added support for handling "HKT" timezone for "event.idm.read_only_udm.metadata.event_timestamp" UDM field.
- event.idm.read_only_udm.security_result.summary: Newly mapped `sec_sum` raw log field with `event.idm.read_only_udm.security_result.summary` UDM field.
2024-10-17 Newly created parser.