Do nothing when a finishing Activity configuration changed

Primary Activity and secondary Activity were both finished
while starting another Activity with FLAG_ACTIVITY_CLEAR_TASK
flag. The secondary container was then removed and the primary
container was resized to fullscreen while the organizer gets
the secondary TaskFragment info-changed event. And the primary
container was removed by primary TaskFragment info-changed event
afterward.

Since the primary Activity was resized before completely being
destroyed. The organizer got an onActivityConfigurationChanged c
allback and resulted in another placeholder activity being launched.

Bug: 236272623
Test: making Duo calls
Change-Id: I851828f739a4937725510d99cbdfae9ed212a023

libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java

@@ -642,6 +642,11 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
     }
 
     private void onActivityConfigurationChanged(@NonNull Activity activity) {
+        if (activity.isFinishing()) {
+            // Do nothing if the activity is currently finishing.
+            return;
+        }
+
         if (isInPictureInPicture(activity)) {
             // We don't embed activity when it is in PIP.
             return;
@@ -1115,6 +1120,10 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
     }
 
     boolean launchPlaceholderIfNecessary(@NonNull Activity activity, boolean isOnCreated) {
+        if (activity.isFinishing()) {
+            return false;
+        }
+
         final TaskFragmentContainer container = getContainerWithActivity(activity);
         // Don't launch placeholder if the container is occluded.
         if (container != null && container != getTopActiveContainer(container.getTaskId())) {