Add annotation for APIs that support Context.getUser/getUserId

/*

 * Copyright (C) 2019 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 android.annotation;

import static java.lang.annotation.ElementType.CONSTRUCTOR;

import static java.lang.annotation.ElementType.METHOD;

import static java.lang.annotation.ElementType.PACKAGE;

import static java.lang.annotation.ElementType.TYPE;

import static java.lang.annotation.RetentionPolicy.SOURCE;

import java.lang.annotation.Retention;

import java.lang.annotation.Target;

/**

 * Indicates an API that uses {@code context.getUser} or {@code context.getUserId}

 * to operate across users (as the user associated with the context)

 * <p>

 * To create a {@link android.content.Context} associated with a different user,

 *  use {@link android.content.Context#createContextAsUser} or

 *  {@link android.content.Context#createPackageContextAsUser}

 * <p>

 * Example:

 * <pre>{@code

 * {@literal @}UserHandleAware

 * public abstract PackageInfo getPackageInfo({@literal @}NonNull String packageName,

 *      {@literal @}PackageInfoFlags int flags) throws NameNotFoundException;

 * }</pre>

 *

 * @memberDoc This method uses {@linkplain android.content.Context#getUser}

 *            or {@linkplain android.content.Context#getUserId} to execute across users.

 * @hide

 */

@Retention(SOURCE)

@Target({TYPE, METHOD, CONSTRUCTOR, PACKAGE})

public @interface UserHandleAware {

}