Pass-thru other panw.panos log types (elastic#19375)

This removes the drop processor from the ingest node pipeline that drops events other than THREAT and TRAFFIC.
This way we can retain the other log data but don't necessarily handle the parsing of it.

Closes elastic#16815

(cherry picked from commit 53b32f9)

CHANGELOG.next.asciidoc

@@ -513,6 +513,8 @@ field. You can revert this change by configuring tags for the module and omittin
 - Add new mode to multiline reader to aggregate constant number of lines {pull}18352[18352]
 - Explicitly set ECS version in all Filebeat modules. {pull}19198[19198]
 - Add awscloudwatch input. {pull}19025[19025]
+- Add automatic retries and exponential backoff to httpjson input. {pull}18956[18956]
+- Changed the panw module to pass through (rather than drop) message types other than threat and traffic. {issue}16815[16815] {pull}19375[19375]
 - Add support for timezone offsets and `Z` to decode_cef timestamp parser. {pull}19346[19346]
 - Improve ECS categorization field mappings in traefik module. {issue}16183[16183] {pull}19379[19379]
 - Improve ECS categorization field mappings in azure module. {issue}16155[16155] {pull}19376[19376]

x-pack/filebeat/module/panw/panos/ingest/pipeline.yml

@@ -197,8 +197,6 @@ processors:
        - intrusion_detection
        - network
      if: 'ctx?._temp_?.message_type == "THREAT"'
- - drop:
-     if: 'ctx?.event?.category == null'
  - append:
      field: event.type
      value: allowed