Releasing 1.9.1 for VOLTHA-2.9 and updating voltha-protos to 5.1.2

Change-Id: I67698ff9c580315bf56e8d192ed11a44c8685ff8
diff --git a/internal/bbsim/devices/olt.go b/internal/bbsim/devices/olt.go
index 6fb3226..cf658eb 100644
--- a/internal/bbsim/devices/olt.go
+++ b/internal/bbsim/devices/olt.go
@@ -20,6 +20,7 @@
 	"context"
 	"encoding/hex"
 	"fmt"
+	"github.com/opencord/voltha-protos/v5/go/extension"
 	"net"
 	"strconv"
 	"sync"
@@ -35,7 +36,6 @@
 	"github.com/looplab/fsm"
 	"github.com/opencord/bbsim/internal/bbsim/packetHandlers"
 	"github.com/opencord/bbsim/internal/common"
-	common_protos "github.com/opencord/voltha-protos/v5/go/common"
 	"github.com/opencord/voltha-protos/v5/go/openolt"
 	"github.com/opencord/voltha-protos/v5/go/tech_profile"
 	log "github.com/sirupsen/logrus"
@@ -1608,8 +1608,8 @@
 	return &openolt.Empty{}, nil
 }
 
-func (o *OltDevice) GetExtValue(ctx context.Context, in *openolt.ValueParam) (*common_protos.ReturnValues, error) {
-	return &common_protos.ReturnValues{}, nil
+func (o *OltDevice) GetExtValue(ctx context.Context, in *openolt.ValueParam) (*extension.ReturnValues, error) {
+	return &extension.ReturnValues{}, nil
 }
 
 func (o *OltDevice) OnuItuPonAlarmSet(ctx context.Context, in *config.OnuItuPonAlarm) (*openolt.Empty, error) {