Determine split leash position by taskId instead of bounds

* Previously we were comparing bounds of the leash to determine
which leash was leftTop vs bottomRight
* That didn't work when we were translating the split apps when
IME is showing in portrait split screen
* Transitions between IME showing to recents animation could
probably use some work, but that itself is not a regression.

Bug: 330714602
Test: Tested on large and small screen with IME up on both apps
No more empty hole

Change-Id: Ie08ac644e5d1bcc48ba57e05e25bbee66afa3d37
diff --git a/quickstep/src/com/android/quickstep/util/TaskViewSimulator.java b/quickstep/src/com/android/quickstep/util/TaskViewSimulator.java
index 1152de2..273b944 100644
--- a/quickstep/src/com/android/quickstep/util/TaskViewSimulator.java
+++ b/quickstep/src/com/android/quickstep/util/TaskViewSimulator.java
@@ -244,7 +244,7 @@
         if (mSplitBounds == null) {
             mStagePosition = STAGE_POSITION_UNDEFINED;
         } else {
-            mStagePosition = mThumbnailPosition.equals(splitInfo.leftTopBounds)
+            mStagePosition = runningTarget.taskId == splitInfo.leftTopTaskId
                     ? STAGE_POSITION_TOP_OR_LEFT : STAGE_POSITION_BOTTOM_OR_RIGHT;
             mPositionHelper.setSplitBounds(convertLauncherSplitBoundsToShell(mSplitBounds),
                     mStagePosition);