Revert "Revert "2/ Add support for remote Recents animation""

This reverts commit 9f8518e532e41ba57916afc49bba72bc23ad3eda.

Reason for revert: Testing relanding changes with ag/3515280

Change-Id: I410bd752c815a5b998a719453def01e00a9d47c8
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index d7a58d9..3f49f0c 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1508,6 +1508,10 @@
         return mTaskStackContainers.getTopStack();
     }
 
+    ArrayList<Task> getVisibleTasks() {
+        return mTaskStackContainers.getVisibleTasks();
+    }
+
     void onStackWindowingModeChanged(TaskStack stack) {
         mTaskStackContainers.onStackWindowingModeChanged(stack);
     }
@@ -3260,6 +3264,16 @@
             return mSplitScreenPrimaryStack;
         }
 
+        ArrayList<Task> getVisibleTasks() {
+            final ArrayList<Task> visibleTasks = new ArrayList<>();
+            forAllTasks(task -> {
+                if (task.isVisible()) {
+                    visibleTasks.add(task);
+                }
+            });
+            return visibleTasks;
+        }
+
         /**
          * Adds the stack to this container.
          * @see DisplayContent#createStack(int, boolean, StackWindowController)