Change log for LINUX_DHCP

Date Changes
2024-09-05 Enhancement-
Added a new Grok pattern to parse new types of unparsed logs of format SYSLOG.
2023-11-10 Enhancement-
Added a new Grok pattern to parse new type of unparsed logs of format SYSLOG.
2022-09-05 Enhancement-
Migrated the custom parsers into default parser.
2022-08-19 Fix-
- Added a new grok for the logs with timestamp of ISO8601 format.
- Mapped sc_summary to security_result.summary.
- Mapped chaddr1 to principal.mac.
2022-08-04 Enhancement
-Parsed logs of type dhcpd which were not handled earlier.
-Added check for ciaddr,chaddr.
-Mapped src_ip to principal.ip.
-Mapped metadata.event_type to STATUS_UPDATE where type includes RELEASE and ciaddr is null.
-Mapped metadata.event_type to STATUS_UPDATE where metadata.event_type to GENERIC_EVENT and src_ip is not null.