Run MediaSessionStub commands in order

Some commands are run asynchronously and subsequent commands need
to wait until the previous one finished. This can be supported
by returning a Future for each command and using the existing
command execution logic to wait for each Future to complete.

As some MediaSessionStub code is now executed delayed to when it
was originally created, we also need to check if the session is
not released before triggering any actions or sending result codes.

Issue: #85
PiperOrigin-RevId: 462101136

RELEASENOTES.md

@@ -15,6 +15,10 @@
         `MetadataRenderer(MetadataOutput, Looper, MetadataDecoderFactory,
         boolean)` to specify whether the renderer will output metadata early or
         in sync with the player position.
+*   Session:
+    *   Ensure commands are always executed in the correct order even if some
+        require asynchronous resolution
+        ([#85](https://github.com/androidx/media/issues/85)).
 
 ### 1.0.0-beta02 (2022-07-15)
 

libraries/session/src/main/java/androidx/media3/session/ConnectedControllersManager.java

@@ -24,7 +24,6 @@
 import androidx.media3.common.Player;
 import androidx.media3.session.MediaSession.ControllerInfo;
 import com.google.common.collect.ImmutableList;
-import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.MoreExecutors;
 import java.util.ArrayDeque;
@@ -227,15 +226,11 @@ public ControllerInfo getController(T controllerKey) {
     }
   }
 
-  public void addToCommandQueue(ControllerInfo controllerInfo, Runnable commandRunnable) {
+  public void addToCommandQueue(ControllerInfo controllerInfo, AsyncCommand asyncCommand) {
     synchronized (lock) {
       @Nullable ConnectedControllerRecord<T> info = controllerRecords.get(controllerInfo);
       if (info != null) {
-        info.commandQueue.add(
-            () -> {
-              commandRunnable.run();
-              return Futures.immediateVoidFuture();
-            });
+        info.commandQueue.add(asyncCommand);
       }
     }
   }