Add missing copyright header to SamlWebFilterIT.java

Change-Id: I26131597c7ae08e5ad60804ffe331508f250587a

src/test/java/com/googlesource/gerrit/plugins/saml/SamlWebFilterIT.java

diff --git a/src/test/java/com/googlesource/gerrit/plugins/saml/SamlWebFilterIT.java b/src/test/java/com/googlesource/gerrit/plugins/saml/SamlWebFilterIT.java
index 249b447..7701b46 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/saml/SamlWebFilterIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/saml/SamlWebFilterIT.java
@@ -1,3 +1,17 @@
+// Copyright (C) 2023 The Android Open Source Project
+//
+// 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 com.googlesource.gerrit.plugins.saml;
 
 import static com.google.common.base.Strings.nullToEmpty;