Add split support for 3P launcher

* Copied logic mostly from
Base/RecentsViewStateController
* There's one KI crash specific to 3P
(b/209694087)
* Swipe to home animation is TODO, but
then again it also seems incorrect for
full-screen app. 3P has many cosmetic issues
throughout.

Bug: 195607777
Test: Tested w/ Nova launcher with grid
and non-grid, able to invoke split screen with
same animations as 1P launcher

Change-Id: I35a1bc92a51caccac4214289e614000cd47bb503

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -1640,7 +1640,13 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         setCurrentPage(mCurrentPage);
     }
 
-    protected void onOrientationChanged() {
+    private void onOrientationChanged() {
+        // If overview is in modal state when rotate, reset it to overview state without running
+        // animation.
+        setModalStateEnabled(false);
+        if (isSplitSelectionActive()) {
+            onRotateInSplitSelectionState();
+        }
     }
 
     // Update task size and padding that are dependent on DeviceProfile and insets.