[VOL-4289]  Proto changes for gRPC migration

Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
diff --git a/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go
new file mode 100644
index 0000000..0d5a811
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go
@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package unix implements a resolver for unix targets.
+package unix
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/internal/transport/networktype"
+	"google.golang.org/grpc/resolver"
+)
+
+const unixScheme = "unix"
+const unixAbstractScheme = "unix-abstract"
+
+type builder struct {
+	scheme string
+}
+
+func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
+	if target.Authority != "" {
+		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.Authority)
+	}
+	addr := resolver.Address{Addr: target.Endpoint}
+	if b.scheme == unixAbstractScheme {
+		// prepend "\x00" to address for unix-abstract
+		addr.Addr = "\x00" + addr.Addr
+	}
+	cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
+	return &nopResolver{}, nil
+}
+
+func (b *builder) Scheme() string {
+	return b.scheme
+}
+
+type nopResolver struct {
+}
+
+func (*nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (*nopResolver) Close() {}
+
+func init() {
+	resolver.Register(&builder{scheme: unixScheme})
+	resolver.Register(&builder{scheme: unixAbstractScheme})
+}