VOL-1460 Migrated to use voltha-protos

Also removed uses of third_party, which didn't seem to be used, and is not currently provided by voltha-protos

Change-Id: I360b9a67adc981912bb96bdcdd4f41354e0b6772
diff --git a/pyvoltha/adapters/extensions/kpi/onu/onu_omci_pm.py b/pyvoltha/adapters/extensions/kpi/onu/onu_omci_pm.py
index 2daf864..98c1129 100644
--- a/pyvoltha/adapters/extensions/kpi/onu/onu_omci_pm.py
+++ b/pyvoltha/adapters/extensions/kpi/onu/onu_omci_pm.py
@@ -13,8 +13,8 @@
 # limitations under the License.
 
 import arrow
-from pyvoltha.protos.device_pb2 import PmConfig, PmGroupConfig
-from pyvoltha.protos.events_pb2 import MetricInformation, MetricMetaData
+from voltha_protos.device_pb2 import PmConfig, PmGroupConfig
+from voltha_protos.events_pb2 import MetricInformation, MetricMetaData
 from pyvoltha.adapters.extensions.kpi.adapter_pm_metrics import AdapterPmMetrics
 from pyvoltha.adapters.extensions.kpi.onu.onu_pm_interval_metrics import OnuPmIntervalMetrics
 from pyvoltha.adapters.extensions.omci.omci_entities import UniG