Retain add button on rotation for two-pane and bottom sheet

Reselects the WidgetCell that was selected when reloading the sheet on
rotation. WidgetsFullSheet is excluded because it does not retain the
open header on rotation.

Bug: 331429554
Test: manual, see screencast
Flag: ACONFIG com.android.launcher3.enable_widget_tap_to_add NEXTFOOD
Change-Id: Id3d21f44b1dc525e144296f513f5a460fc51474c