Select remote apps based on stagePosition instead of hardcoded values

* LauncherSplitScreenListener returns taskIds guaranteeing index 0
to be leftTop task and index 1 to be rightBottom. Use that
instead of assuming remote target index 0 will be leftTop and
index 1 is right bottom as provided

Bug: 181704764

Change-Id: I2bc358ff3c2f2d127b81e10824e2c13f3ad718df

quickstep/src/com/android/quickstep/SwipeUpAnimationLogic.java

@@ -289,9 +289,11 @@ public abstract class SwipeUpAnimationLogic implements
                 mRemoteTargetHandles[0].mTaskViewSimulator.setPreview(primaryTaskTarget);
             }
         } else {
+            int[] taskIds = LauncherSplitScreenListener.INSTANCE.getNoCreate()
+                    .getRunningSplitTaskIds();
             // We're in staged split
-            primaryTaskTarget = targets.apps[0];
-            secondaryTaskTarget = targets.apps[1];
+            primaryTaskTarget = targets.findTask(taskIds[0]);
+            secondaryTaskTarget = targets.findTask(taskIds[1]);
             mStagedSplitBounds = new SplitConfigurationOptions.StagedSplitBounds(
                     primaryTaskTarget.screenSpaceBounds,
                     secondaryTaskTarget.screenSpaceBounds, dividerTarget.screenSpaceBounds);

quickstep/src/com/android/quickstep/util/TaskViewSimulator.java

@@ -51,8 +51,8 @@ import com.android.systemui.shared.system.SyncRtSurfaceTransactionApplierCompat.
  */
 public class TaskViewSimulator implements TransformParams.BuilderProxy {
 
-    private final String TAG = "TaskViewSimulator";
-    private final boolean DEBUG = false;
+    private static final String TAG = "TaskViewSimulator";
+    private static final boolean DEBUG = false;
 
     private final Rect mTmpCropRect = new Rect();
     private final RectF mTempRectF = new RectF();