onu start collecting pm metrics

Change-Id: If449f565cb28d33dfa6aa30a1bd4930feae91820
diff --git a/python/adapters/brcm_openomci_onu/brcm_openomci_onu_handler.py b/python/adapters/brcm_openomci_onu/brcm_openomci_onu_handler.py
index 4e86684..bcd4fc4 100644
--- a/python/adapters/brcm_openomci_onu/brcm_openomci_onu_handler.py
+++ b/python/adapters/brcm_openomci_onu/brcm_openomci_onu_handler.py
@@ -253,6 +253,10 @@
             # Note, ONU ID and UNI intf set in add_uni_port method
             self._onu_omci_device.alarm_synchronizer.set_alarm_params(mgr=self.alarms,
                                                                       ani_ports=[self._pon])
+
+            #Start collecting stats from the device after a brief pause
+            reactor.callLater(10, self.pm_metrics.start_collector)
+
             self.enabled = True
         else:
             self.log.info('onu-already-activated')