[otel-tracing] vendor and go modules changes

This tracks all the vendor file changes and changes to go modules due
to OpenTelemetry support

Signed-off-by: Alakesh Haloi <alakeshh@amazon.com>

vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go

@@ -0,0 +1,62 @@
+package runtime
+
+import (
+	"io"
+
+	"errors"
+	"github.com/golang/protobuf/proto"
+	"io/ioutil"
+)
+
+// ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
+type ProtoMarshaller struct{}
+
+// ContentType always returns "application/octet-stream".
+func (*ProtoMarshaller) ContentType() string {
+	return "application/octet-stream"
+}
+
+// Marshal marshals "value" into Proto
+func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error) {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return nil, errors.New("unable to marshal non proto field")
+	}
+	return proto.Marshal(message)
+}
+
+// Unmarshal unmarshals proto "data" into "value"
+func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return errors.New("unable to unmarshal non proto field")
+	}
+	return proto.Unmarshal(data, message)
+}
+
+// NewDecoder returns a Decoder which reads proto stream from "reader".
+func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder {
+	return DecoderFunc(func(value interface{}) error {
+		buffer, err := ioutil.ReadAll(reader)
+		if err != nil {
+			return err
+		}
+		return marshaller.Unmarshal(buffer, value)
+	})
+}
+
+// NewEncoder returns an Encoder which writes proto stream into "writer".
+func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder {
+	return EncoderFunc(func(value interface{}) error {
+		buffer, err := marshaller.Marshal(value)
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(buffer)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+}