Add two panel home support for page binding logic

There's a logic which prioritizes the binding for the
current page and defers the other pages' binding.
If two panel home is enabled, we want to bind both pages
together. LauncherPageRestoreHelper has been created to
contain the logic for persisting restoring and calculating
which pages to load immediately.

Test: manual + run LauncherPageRestoreHelperTest robo test
Bug: 174464691
Change-Id: I57ac3f7150303b95b272e922f44bda26f9d5ce2a
diff --git a/src/com/android/launcher3/DeleteDropTarget.java b/src/com/android/launcher3/DeleteDropTarget.java
index 80ec192..ba55834 100644
--- a/src/com/android/launcher3/DeleteDropTarget.java
+++ b/src/com/android/launcher3/DeleteDropTarget.java
@@ -33,6 +33,7 @@
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.model.data.LauncherAppWidgetInfo;
 import com.android.launcher3.model.data.WorkspaceItemInfo;
+import com.android.launcher3.util.IntSet;
 import com.android.launcher3.views.Snackbar;
 
 public class DeleteDropTarget extends ButtonDropTarget {
@@ -131,7 +132,7 @@
             onAccessibilityDrop(null, item);
             ModelWriter modelWriter = mLauncher.getModelWriter();
             Runnable onUndoClicked = () -> {
-                mLauncher.setPageToBindSynchronously(itemPage);
+                mLauncher.setPagesToBindSynchronously(IntSet.wrap(itemPage));
                 modelWriter.abortDelete();
                 mLauncher.getStatsLogManager().logger().log(LAUNCHER_UNDO);
             };