Change log for ZSCALER_ZPA_AUDIT

Date Changes
2025-11-18 - `Session Time Out`: Added support for the event `Session Time Out` and relevant corresponding raw log fields.
2025-10-16 - Updated the grok pattern to handle the ModifiedBy, ObjectID, and CustomerID raw log fields.
2025-04-30 - Promoted ZSCALER_ZPA_AUDIT Premium parser to default. You can see full details in the parser configuration page - https://cloud.google.com/chronicle/docs/ingestion/default-parsers/ingest-zscaler-logs