[VOL-3548] Differentiate between OLT gRPC channel
disconnect and device reboot

Change-Id: I3df869575f21e6319919b2e540d85d47fe71dc74
diff --git a/protos/voltha_protos/openolt.proto b/protos/voltha_protos/openolt.proto
index 8f22e35..6b525ce 100644
--- a/protos/voltha_protos/openolt.proto
+++ b/protos/voltha_protos/openolt.proto
@@ -369,6 +369,7 @@
     string firmware_version = 4;
     string device_id = 16;
     string device_serial_number = 17;
+    bool previously_connected = 19; // used to indicate agent reconcile status
 
     // Total number of pon intf ports on the device
     fixed32 pon_ports = 12;