Update protobuf,grpc,etcd dependencies

1. Updated etcd/protobuf/grpc dependencies:

echo "
hack/pin-dependency.sh github.com/golang/protobuf latest
hack/pin-dependency.sh google.golang.org/protobuf latest
hack/pin-dependency.sh go.etcd.io/etcd/api/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/client/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/client/pkg/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/pkg/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/server/v3 v3.5.0-rc.0
hack/pin-dependency.sh go.etcd.io/etcd/tests/v3 v3.5.0-rc.0
hack/pin-dependency.sh google.golang.org/grpc latest
" | bash

2. Linted transitive dependencies until versions are clean:

hack/lint-dependencies.sh  | grep "  hack/pin-dependency.sh" | bash

3. Linted dependencies until dropped versions are clean:

hack/lint-dependencies.sh  | grep "dropreplace" | bash

4. Updated vendor and internal modules:

hack/update-vendor.sh
hack/update-internal-modules.sh

Repeated steps 2-4 until clean

vendor/github.com/grpc-ecosystem/go-grpc-middleware/logging/settable/logsettable.go

@@ -0,0 +1,99 @@
+package grpc_logsettable
+
+import (
+	"io/ioutil"
+	"sync"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+// SettableLoggerV2 is thread-safe.
+type SettableLoggerV2 interface {
+	grpclog.LoggerV2
+	// Sets given logger as the underlying implementation.
+	Set(loggerv2 grpclog.LoggerV2)
+	// Sets `discard` logger as the underlying implementation.
+	Reset()
+}
+
+// ReplaceGrpcLoggerV2 creates and configures SettableLoggerV2 as grpc logger.
+func ReplaceGrpcLoggerV2() SettableLoggerV2 {
+	settable := &settableLoggerV2{}
+	settable.Reset()
+	grpclog.SetLoggerV2(settable)
+	return settable
+}
+
+// SettableLoggerV2 implements SettableLoggerV2
+type settableLoggerV2 struct {
+	log grpclog.LoggerV2
+	mu  sync.RWMutex
+}
+
+func (s *settableLoggerV2) Set(log grpclog.LoggerV2) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.log = log
+}
+
+func (s *settableLoggerV2) Reset() {
+	s.Set(grpclog.NewLoggerV2(ioutil.Discard, ioutil.Discard, ioutil.Discard))
+}
+
+func (s *settableLoggerV2) get() grpclog.LoggerV2 {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.log
+}
+
+func (s *settableLoggerV2) Info(args ...interface{}) {
+	s.get().Info(args)
+}
+
+func (s *settableLoggerV2) Infoln(args ...interface{}) {
+	s.get().Infoln(args)
+}
+
+func (s *settableLoggerV2) Infof(format string, args ...interface{}) {
+	s.get().Infof(format, args)
+}
+
+func (s *settableLoggerV2) Warning(args ...interface{}) {
+	s.get().Warning(args)
+}
+
+func (s *settableLoggerV2) Warningln(args ...interface{}) {
+	s.get().Warningln(args)
+}
+
+func (s *settableLoggerV2) Warningf(format string, args ...interface{}) {
+	s.get().Warningf(format, args)
+}
+
+func (s *settableLoggerV2) Error(args ...interface{}) {
+	s.get().Error(args)
+}
+
+func (s *settableLoggerV2) Errorln(args ...interface{}) {
+	s.get().Errorln(args)
+}
+
+func (s *settableLoggerV2) Errorf(format string, args ...interface{}) {
+	s.get().Errorf(format, args)
+}
+
+func (s *settableLoggerV2) Fatal(args ...interface{}) {
+	s.get().Fatal(args)
+}
+
+func (s *settableLoggerV2) Fatalln(args ...interface{}) {
+	s.get().Fatalln(args)
+}
+
+func (s *settableLoggerV2) Fatalf(format string, args ...interface{}) {
+	s.get().Fatalf(format, args)
+}
+
+func (s *settableLoggerV2) V(l int) bool {
+	return s.get().V(l)
+}