Adding initial implementation of Prediction client/service API

Test: Build sample app, ensure that app prediction service gets client
      requests
Bug: 111701043
Change-Id: I33aceb2de31552b2d740dc333559d68728753e40
Signed-off-by: Winson Chung <winsonc@google.com>
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index eb7be6f..1626d30 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -3975,6 +3975,15 @@
     public static final String CONTENT_CAPTURE_MANAGER_SERVICE = "content_capture";
 
     /**
+     * Official published name of the app prediction service.
+     *
+     * @hide
+     * @see #getSystemService(String)
+     */
+    @SystemApi
+    public static final String APP_PREDICTION_SERVICE = "app_prediction";
+
+    /**
      * Use with {@link #getSystemService(String)} to access the
      * {@link com.android.server.voiceinteraction.SoundTriggerService}.
      *