Remove using hidden API: MediaSessionManager(Context)

Replace with SystemServiceRegistry.registerContextAwareService,
which is a @SystemApi. See ag/9734296 for reference.

Bug: 160380016
Test: atest
    CtsMediaTestCases:android.media.cts.MediaSessionManagerTest
Change-Id: I9b6da97e0e0f5181ce8681a399ca090e67f6fd4e

core/java/android/app/SystemServiceRegistry.java

@@ -101,11 +101,11 @@ import android.location.ICountryDetector;
 import android.location.ILocationManager;
 import android.location.LocationManager;
 import android.media.AudioManager;
+import android.media.MediaFrameworkInitializer;
 import android.media.MediaRouter;
 import android.media.midi.IMidiManager;
 import android.media.midi.MidiManager;
 import android.media.projection.MediaProjectionManager;
-import android.media.session.MediaSessionManager;
 import android.media.soundtrigger.SoundTriggerManager;
 import android.media.tv.ITvInputManager;
 import android.media.tv.TvInputManager;
@@ -855,13 +855,6 @@ public final class SystemServiceRegistry {
                 return new ConsumerIrManager(ctx);
             }});
 
-        registerService(Context.MEDIA_SESSION_SERVICE, MediaSessionManager.class,
-                new CachedServiceFetcher<MediaSessionManager>() {
-            @Override
-            public MediaSessionManager createService(ContextImpl ctx) {
-                return new MediaSessionManager(ctx);
-            }});
-
         registerService(Context.TRUST_SERVICE, TrustManager.class,
                 new StaticServiceFetcher<TrustManager>() {
             @Override
@@ -1335,6 +1328,7 @@ public final class SystemServiceRegistry {
             WifiFrameworkInitializer.registerServiceWrappers();
             StatsFrameworkInitializer.registerServiceWrappers();
             RollbackManagerFrameworkInitializer.initialize();
+            MediaFrameworkInitializer.registerServiceWrappers();
         } finally {
             // If any of the above code throws, we're in a pretty bad shape and the process
             // will likely crash, but we'll reset it just in case there's an exception handler...

media/java/android/media/MediaFrameworkInitializer.java

@@ -17,6 +17,9 @@
 package android.media;
 
 import android.annotation.NonNull;
+import android.app.SystemServiceRegistry;
+import android.content.Context;
+import android.media.session.MediaSessionManager;
 
 import com.android.internal.util.Preconditions;
 
@@ -53,4 +56,19 @@ public class MediaFrameworkInitializer {
     public static MediaServiceManager getMediaServiceManager() {
         return sMediaServiceManager;
     }
+
+    /**
+     * Called by {@link SystemServiceRegistry}'s static initializer and registers all media
+     * services to {@link Context}, so that {@link Context#getSystemService} can return them.
+     *
+     * @throws IllegalStateException if this is called from anywhere besides
+     * {@link SystemServiceRegistry}
+     */
+    public static void registerServiceWrappers() {
+        SystemServiceRegistry.registerContextAwareService(
+                Context.MEDIA_SESSION_SERVICE,
+                MediaSessionManager.class,
+                context -> new MediaSessionManager(context)
+        );
+    }
 }