Change log for GCP_DNS

Date Changes
2026-06-02 principal.hostname
2026-03-17 Improved the grok pattern to extract the correct values from the `jsonPayload.queryName` raw log fields and mapped them to the `network.dns.questions.name` UDM field.
2025-07-01 principal.namespace
2024-12-16 Promoted GCP_DNS parser to default.