add missing header in httpstream_test.go; whitespace in imports

Author: azych

staging/src/k8s.io/kubelet/pkg/cri/streaming/remotecommand/httpstream_test.go

@@ -1,3 +1,19 @@
+/*
+Copyright 2025 The Kubernetes 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 remotecommand
 
 import (
@@ -9,6 +25,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"go.uber.org/goleak"
+
 	"k8s.io/client-go/tools/remotecommand"
 )