Correct license header for VisibilityCacheTest

I48597e49 (Add tests for VisibilityCache, 2019-04-08) accidentally
used the JGit license header using the Eclipse Distribution License
instead of the Gitiles license header using the Apache License.
Update to use the latter.

The exact license header text comes from
https://opensource.google/docs/releasing/preparing/#Apache-header

Change-Id: I42e1c6e925af1463718b37889c6fa1816c5d2a81
Signed-off-by: Jonathan Nieder <jrn@google.com>
diff --git a/javatests/com/google/gitiles/VisibilityCacheTest.java b/javatests/com/google/gitiles/VisibilityCacheTest.java
index bcc2b40..f22cf02 100644
--- a/javatests/com/google/gitiles/VisibilityCacheTest.java
+++ b/javatests/com/google/gitiles/VisibilityCacheTest.java
@@ -1,45 +1,16 @@
-/*
- * Copyright (C) 2019, Google LLC.
- * and other copyright owners as documented in the project's IP log.
- *
- * This program and the accompanying materials are made available
- * under the terms of the Eclipse Distribution License v1.0 which
- * accompanies this distribution, is reproduced below, and is
- * available at http://www.eclipse.org/org/documents/edl-v10.php
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * - Redistributions of source code must retain the above copyright
- *   notice, this list of conditions and the following disclaimer.
- *
- * - Redistributions in binary form must reproduce the above
- *   copyright notice, this list of conditions and the following
- *   disclaimer in the documentation and/or other materials provided
- *   with the distribution.
- *
- * - Neither the name of the Eclipse Foundation, Inc. nor the
- *   names of its contributors may be used to endorse or promote
- *   products derived from this software without specific prior
- *   written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
+// Copyright 2019 Google LLC
+//
+// 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
+//
+//     https://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.google.gitiles;
 
 import static com.google.common.truth.Truth.assertThat;