protected void collectLabels(final SortedArrayStringMap contextData) {
        contextData.putValue("labels", labels);
        labels.forEach((key, value) -> contextData.putValue("label-%s".formatted(key), value));
    }
Build google cloud appender.

@param name           the name
@param projectId      the project id
@param flattenMessage the flatten message
@param appenderRef    the appender ref
@param filter         the filter
@param config         the config
@return the google cloud appender
support/cas-server-support-gcp-logging/src/main/java/org/apereo/cas/logging/GoogleCloudAppender.java