[VOL-2570]Make skew configurable for performance metrics

Change-Id: Ifa7ab7f04c58d47a48bfa1ebd517c17ddde51358
diff --git a/VERSION b/VERSION
index 69fa968..437459c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.5.0-dev
+2.5.0
diff --git a/pyvoltha/adapters/extensions/events/kpi/adapter_pm_metrics.py b/pyvoltha/adapters/extensions/events/kpi/adapter_pm_metrics.py
index 34cff6e..0a34033 100644
--- a/pyvoltha/adapters/extensions/events/kpi/adapter_pm_metrics.py
+++ b/pyvoltha/adapters/extensions/events/kpi/adapter_pm_metrics.py
@@ -40,7 +40,7 @@
     TIMESTAMP_ATTRIBUTE = 'timestamp'
 
     def __init__(self, event_mgr, core_proxy, device_id, logical_device_id, serial_number,
-                 grouped=False, freq_override=False, **kwargs):
+                 grouped=False, freq_override=False, max_skew=5, **kwargs):
         """
         Initializer for shared Device Adapter PM metrics manager
 
@@ -68,6 +68,7 @@
         self.freq_override = grouped and freq_override
         self.lc = None
         self.pm_group_metrics = dict()      # name -> PmGroupConfig
+        self.max_skew = max_skew
 
     def update(self, pm_config):
         # TODO: Move any common steps into base class
diff --git a/pyvoltha/adapters/extensions/events/kpi/onu/onu_pm_metrics.py b/pyvoltha/adapters/extensions/events/kpi/onu/onu_pm_metrics.py
index 1fb29b6..e3671f5 100644
--- a/pyvoltha/adapters/extensions/events/kpi/onu/onu_pm_metrics.py
+++ b/pyvoltha/adapters/extensions/events/kpi/onu/onu_pm_metrics.py
@@ -91,11 +91,15 @@
                 self.stop_collector()
                 self.start_collector()
 
+            if self.max_skew != pm_config.max_skew:
+                self.max_skew = pm_config.max_skew
+
             if pm_config.grouped:
                 for group in pm_config.groups:
                     group_config = self.pm_group_metrics.get(group.group_name)
                     if group_config is not None:
                         group_config.enabled = group.enabled
+
             else:
                 msg = 'There are no independent ONU metrics, only group metrics at this time'
                 raise NotImplemented(msg)
@@ -111,7 +115,8 @@
             pm_config = PmConfigs(id=self.device_id,
                                   default_freq=self.default_freq,
                                   grouped=self.grouped,
-                                  freq_override=self.freq_override)
+                                  freq_override=self.freq_override,
+                                  max_skew=self.max_skew)
         metrics = set()
 
         if self._heartbeat is not None: