private static void setMetaInfo(MetricsPacket.Builder builder, Instant timestamp) {
        builder.timestamp(timestamp)
                .statusCode(0)
                .statusMessage("Data collected successfully");
    }
Returns the metrics to output for the given service, with updated timestamp
In order to include a metric, it must exist in the given map of metric to consumers.
Each returned metric will contain a collection of consumers that it should be routed to.
metrics-proxy/src/main/java/ai/vespa/metricsproxy/core/VespaMetrics.java