What license(s) are the Android support libraries released under?

Question

Each source file, (like this one) contains a copyright header like this:

/*
 * Copyright (C) 2011 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.
 */

Which states an Apache license:

http://www.apache.org/licenses/LICENSE-2.0

And, I think apache license allows derivative works to be built and sold. Still, you should:

1. Include same license in source of the derived product as well.
2. Clearly state what parts you derived changes, built upon.

You can place this in Licence.txt or Readme.txt at the root of your project.

Look into your NOTICE.txt file in your android/support folder. Quote: "The Android Open Source Project. Licensed under the Apache License, Version 2.0, [...], http://www.apache.org/licenses/".

Look at this file (Local Maven repository for Support Libraries is subset of this path):

https://android.googlesource.com/platform/prebuilts/maven_repo/android/+/master/NOTICE.txt

Notice for all the files in this folder.

…

Copyright (c) 2005-2013, The Android Open Source Project

…

Apache License Version 2.0, January 2004

…