test: fix encoding of unique id for bigtable integration tests
@@ -2424,7 +2424,7 @@ func TestIntegration_AdminBackup(t *testing.T) {
defer iAdminClient.Close()
uniqueID := make([]byte, 8)
_, err = rand.Read(uniqueID)
- diffInstance := testEnv.Config().Instance + "-d" + string(uniqueID)
+ diffInstance := fmt.Sprintf("%s-d-%x", testEnv.Config().Instance, uniqueID)
diffCluster := sourceCluster + "-d"
conf := &InstanceConf{
InstanceId: diffInstance,
