VOL-3589 Update voltha go to support new version v4 of voltha protos

Change-Id: I32074b5c05b08f8ebd2205f8dc2af225bff465cc
diff --git a/rw_core/core/device/agent_flow.go b/rw_core/core/device/agent_flow.go
index e49fa14..8b8e1a7 100644
--- a/rw_core/core/device/agent_flow.go
+++ b/rw_core/core/device/agent_flow.go
@@ -21,10 +21,10 @@
 
 	"github.com/gogo/protobuf/proto"
 	coreutils "github.com/opencord/voltha-go/rw_core/utils"
-	fu "github.com/opencord/voltha-lib-go/v3/pkg/flows"
-	"github.com/opencord/voltha-lib-go/v3/pkg/log"
-	ofp "github.com/opencord/voltha-protos/v3/go/openflow_13"
-	"github.com/opencord/voltha-protos/v3/go/voltha"
+	fu "github.com/opencord/voltha-lib-go/v4/pkg/flows"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
+	ofp "github.com/opencord/voltha-protos/v4/go/openflow_13"
+	"github.com/opencord/voltha-protos/v4/go/voltha"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )