Vector overwrites the log_type when writing a message to syslog that includes its own log_type field in RHOL

Issue

• A log message produced by an application that contains log_type: openshift_audit is labelled by the collector as audit log type instead of application
• Log messages forwarded to syslog by Vector are incorrectly forwarded as audit_log messages when original log line includes a log_type field
• When a log produced contains the log_type field in the message, the log_type from the original log overwrites the expected log_type value that the Vector collector sets