VOL-4499: Update 'device_flow' struct to have the flow_type. This
will enable the voltha openolt adapter to just send the voltha-flow-id
and the agent can retrieve the flow_type automatically from the
device_flow struct.

VOL-4520: Allow configurability of MAC Device Activation delay time.
With BAL3.10.2.2 it is observed the Edgecore OLTs sometimes need more
time to do the Maple/Aspen download procedure as part of MAC activation.
The current 200ms delay has recomendded to increase to 2s as a
workaround by Edgecore (ticket #19146). This patch makes this delay
configurable on a per platform basis.

Version bumped to 3.6.3

Change-Id: I3bac3af423aa6374c10302519cd21a481d5a4a86
diff --git a/agent/src/core_data.h b/agent/src/core_data.h
index 576c248..d7405fb 100644
--- a/agent/src/core_data.h
+++ b/agent/src/core_data.h
@@ -191,6 +191,7 @@
                                        // 0 value means invalid or not-applicable
                                        // Applicable for bi-directional data path flows (one flow per direction)
                                        // Symmetric flows should share the same device_flow_id.
+    std::string flow_type; // upstream, downstream, multicast
 
 } device_flow;