Support desktop tasks in recents animation

Desktop tasks are using freeform windowing mode. Update recents
animation to support freeform tasks when desktop mode feature flag is
enabled.

Changes:
- set initial size for freeform tasks to be the size of the thumbnail
  instead of size of the screen
- support multiple individual remote animation targets when starting the
  recents animation

TODO:
- there are flickers when starting and ending the recents animation

Bug: 263264985
Test: swipe up when more than 1 desktop task is visible
Change-Id: I27ee02774281b3a433d779c0bb8825cdb6ea5457

quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java

@@ -127,6 +127,7 @@ import com.android.quickstep.util.SurfaceTransaction;
 import com.android.quickstep.util.SurfaceTransactionApplier;
 import com.android.quickstep.util.SwipePipToHomeAnimator;
 import com.android.quickstep.util.TaskViewSimulator;
+import com.android.quickstep.views.DesktopTaskView;
 import com.android.quickstep.views.RecentsView;
 import com.android.quickstep.views.TaskView;
 import com.android.systemui.shared.recents.model.Task;
@@ -877,7 +878,11 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
     public void onRecentsAnimationStart(RecentsAnimationController controller,
             RecentsAnimationTargets targets) {
         super.onRecentsAnimationStart(controller, targets);
-        mRemoteTargetHandles = mTargetGluer.assignTargetsForSplitScreen(mContext, targets);
+        if (DesktopTaskView.DESKTOP_MODE_SUPPORTED && targets.hasDesktopTasks()) {
+            mRemoteTargetHandles = mTargetGluer.assignTargetsForDesktop(targets);
+        } else {
+            mRemoteTargetHandles = mTargetGluer.assignTargetsForSplitScreen(mContext, targets);
+        }
         mRecentsAnimationController = controller;
         mRecentsAnimationTargets = targets;
         mSwipePipToHomeReleaseCheck = new RemoteAnimationTargets.ReleaseCheck();