Add annotation for APIs that support Context.getUser/getUserId

Annotation for APIs that use context.getUser/getUserId to execute as other users

Bug:143738055
Test: -
Change-Id: Ieeb54812bcdc5ce0b8ee4a7cfd37aa692712efd6

core/java/android/annotation/UserHandleAware.java

@@ -0,0 +1,49 @@
+/*
+ * 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 {
+}