create constant for errors requiring backoff

receiver/kafkareceiver/kafka_receiver.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"slices"
 	"strconv"
 	"sync"
 	"time"
@@ -38,6 +39,10 @@ const (
 
 var errInvalidInitialOffset = errors.New("invalid initial offset")
 
+var errorsRequiringBackoff = []error{
+	errors.New("data refused due to high memory usage"), // error returned by memory limiter processor
+}
+
 // kafkaTracesConsumer uses sarama to consume and handle messages from kafka.
 type kafkaTracesConsumer struct {
 	config            Config
@@ -628,7 +633,7 @@ func (c *tracesConsumerGroupHandler) ConsumeClaim(session sarama.ConsumerGroupSe
 }
 
 func errorRequiresBackoff(err error) bool {
-	return err.Error() == "data refused due to high memory usage"
+	return slices.Contains(errorsRequiringBackoff, err)
 }
 
 func (c *metricsConsumerGroupHandler) Setup(session sarama.ConsumerGroupSession) error {