Reparent folders and app pairs

Previously, app pairs and folders shared a common data model, FolderInfo. Now we need to separate them, so a new type, CollectionInfo, will serve as the parent of both types.

Bug: 315731527
Fixes: 326664798
Flag: ACONFIG com.android.wm.shell.enable_app_pairs TRUNKFOOD
Test: Manual, unit tests to follow
Change-Id: Ia8c429cf6e6a376f2554ae1866549ef0bcab2a22

src/com/android/launcher3/model/AddWorkspaceItemsTask.java

@@ -31,7 +31,7 @@ import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.logging.FileLog;
 import com.android.launcher3.model.BgDataModel.Callbacks;
 import com.android.launcher3.model.data.AppInfo;
-import com.android.launcher3.model.data.FolderInfo;
+import com.android.launcher3.model.data.CollectionInfo;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.model.data.ItemInfoWithIcon;
 import com.android.launcher3.model.data.LauncherAppWidgetInfo;
@@ -131,8 +131,8 @@ public class AddWorkspaceItemsTask extends BaseModelUpdateTask {
                 int screenId = coords[0];
 
                 ItemInfo itemInfo;
-                if (item instanceof WorkspaceItemInfo || item instanceof FolderInfo ||
-                        item instanceof LauncherAppWidgetInfo) {
+                if (item instanceof WorkspaceItemInfo || item instanceof CollectionInfo
+                        || item instanceof LauncherAppWidgetInfo) {
                     itemInfo = item;
                 } else if (item instanceof WorkspaceItemFactory) {
                     itemInfo = ((WorkspaceItemFactory) item).makeWorkspaceItem(app.getContext());