Function serve_telemetry 

pub fn serve_telemetry(
    monitor_svc_proxy: DeviceMonitorProxy,
    cobalt_proxy: MetricEventLoggerProxy,
    inspect_node: Node,
    external_inspect_node: Node,
    persistence_req_sender: PersistenceReqSender,
    defect_sender: Sender<Defect>,
) -> (TelemetrySender, impl Future<Output = ()>)

Create a struct for sending TelemetryEvent, and a future representing the telemetry loop.

Every 15 seconds, the telemetry loop will query for MLME/PHY stats and update various time-interval stats. The telemetry loop also handles incoming TelemetryEvent to update the appropriate stats.