Remove unhelpful prefab samples.

These don't demonstrate any NDK behavior, just AGP behavior. The
dependency management they show is also shown elsewhere since we rely on
these features for sharing code between samples anyway.

Author: DanAlbert

prefab/README.md

@@ -1,94 +1,15 @@
-# Prefab Samples
+# Sample removed
 
-The samples in this directory demonstrate how to create and consume
-[C/C++ dependencies] with the Android Gradle Plugin. Dependencies are packaged
-within AARs using the [Prefab] package format. The Android Gradle Plugin
-natively supports producing and consuming these, so you do not need to worry
-about the details of the packaging format.
+The samples that used to reside in this directory have been removed. The
+behaviors demonstrated here (publication and consumption of AARs with native
+APIs) are now used throughout the samples for code sharing, and were Android
+Gradle Plugin features rather than NDK features.
 
-The individual samples will explain in more detail, but the typical workflow for
-a consumer of a native dependency is:
+For an example of how to create an AAR that exposes a native library, see the
+`base` module, or any other with `buildFeatures { prefabPublishing = true }`.
 
-1. Enable the prefab build feature in your `build.gradle` file.
-1. Add the dependency to the dependencies block of your `build.gradle` file.
-1. Import the package in your `CMakeLists.txt` or `Android.mk` file.
-1. Link the dependencies to your libraries.
+For examples of how to consume native APIs from an AAR, see any of the other
+samples which set `buildFeatures { prefab = true }`.
 
-Linking the dependency to your library will automatically make the headers
-available, link the required libraries, and include the dependencies you use in
-your application or library.
-
-To produce an AAR that exposes C/C++ APIs:
-
-1. Enable the `prefabPublishing` build feature in your `build.gradle` file.
-1. Use `android.prefab` in your `build.gradle` file to declare the names of the
-   libraries you wish to export and the headers that define their interface.
-
-To test your packages, follow the steps for package consumers. Note that until
-https://issuetracker.google.com/120166563 is fixed it is not possible to depend
-on the native components of an AAR generated by another module of the same
-project when using Android Studio. Instead, test in a separate project. You can
-import the AAR into your test project either
-[directly](https://developer.android.com/studio/projects/android-library#AddDependency)
-or by publishing it to a Maven repository.
-
-With that in mind, the samples here collectively demonstrate prefab usage:
-
-- prefab-publishing shows how to create an AAR for distributing native libraries
-- prefab-dependency shows how to import native dependencies from [GMaven]
-- curl-ssl: for shows to use 2 very specific and important AARs (curl and ssl)
-
-## Prefab Availability
-
-Support for Prefab packages has been available Android Gradle Plugin since
-version 4.0:
-
-- Consuming native dependencies requires AGP 4.0+
-- Generating AARs that export native dependencies requires AGP 4.1+
-
-The AARs used by the samples here are hosted at [Google Maven], but you can host
-your AARs anywhere accessible to gradle.
-
-## Pre-requisites
-
-- Android Gradle Plugin 4.0+
-- The [Android NDK](https://developer.android.com/ndk/)
-
-Please check for the individial sample's README.md for anything specific to that
-sample.
-
-## Support
-
-If you've found an error in these samples, please
-[file an issue](https://github.com/android/ndk-samples/issues/new).
-
-Patches are encouraged, and may be submitted by
-[forking this project](https://github.com/android/ndk-samples/fork) and
-submitting a pull request through GitHub. Please see
-[CONTRIBUTING.md](../CONTRIBUTING.md) for more details.
-
-- [Stack Overflow](http://stackoverflow.com/questions/tagged/android-ndk)
-- [Android Tools Feedbacks](http://tools.android.com/feedback)
-
-## License
-
-Copyright 2020 Google, Inc.
-
-Licensed to the Apache Software Foundation (ASF) under one or more contributor
-license agreements. See the NOTICE file distributed with this work for
-additional information regarding copyright ownership. The ASF licenses this file
-to you 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.
-
-[c/c++ dependencies]: https://developer.android.com/studio/build/native-dependencies?buildsystem=cmake&agpversion=4.0
-[gmaven]: (https://maven.google.com/web/index.html?q=ndk#com.android.ndk.thirdparty)
-[google maven]: https://maven.google.com/web/index.html#com.android.ndk.thirdparty
-[prefab]: https://google.github.io/prefab
+See https://developer.android.com/build/native-dependencies for the Android
+Gradle Plugin's documentation of these features.