Change log for NETFILTER_IPTABLES

Date Changes
2023-10-12 Enhancement:
- Added a Grok pattern to parse SYSLOG type logs.
- Mapped "OUT" to "target.resource.attribute.labels".
- Mapped "IN" to "principal.resource.attribute.labels".
2022-10-12 Enhancement:
- Added new grok to parse unparsed logs(logs with header format <133> Sep 29 01:38:26).
- Mapped security_result.action to Block where action is reject.
2022-10-04 Enhancement:
- Remapped "src_host" to "intermediary.hostname" instead of "principal.hostname".
2022-06-21 Enhancement:
- Mapped "TOS" with "tos_label" to "event.idm.read_only_udm.additional.fields".
- Mapped "LEN" with "len_label" to "event.idm.read_only_udm.additional.fields".
- Mapped "URGP" with "urgp_label" to "event.idm.read_only_udm.additional.fields".
- Mapped "PREC" with "prec_label" to "event.idm.read_only_udm.additional.fields".
- Mapped "SPI" with "spi_label" to "event.idm.read_only_udm.additional.fields".
- Mapped "CODE" with "code_label" to "event.idm.read_only_udm.additional.fields".
- Mapped "DF" with "df_label" to "event.idm.read_only_udm.additional.fields".
- If "action" is "DROP" then "security_result.action" is assigned with "BLOCK".