Two panel home empty page removing logic change

- Don't remove a single page if it's empty, only if both pages are empty.
- Add back empty pages after they were removed while the phone
  was on single panel home.
- On two panel home don't add new workspace items onto the second screen

Test: manual
Bug: 196376162
Change-Id: I4c54ffa3b359a236deb3ab67adb54111e77ec896

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

@@ -16,6 +16,7 @@
 package com.android.launcher3.model;
 
 import static com.android.launcher3.WorkspaceLayoutManager.FIRST_SCREEN_ID;
+import static com.android.launcher3.WorkspaceLayoutManager.SECOND_SCREEN_ID;
 
 import android.content.Intent;
 import android.content.pm.LauncherActivityInfo;
@@ -299,6 +300,11 @@ public class AddWorkspaceItemsTask extends BaseModelUpdateTask {
         IntSet screensToExclude = new IntSet();
         if (FeatureFlags.QSB_ON_FIRST_SCREEN) {
             screensToExclude.add(FIRST_SCREEN_ID);
+
+            // On split display we don't want to add the new items onto the second screen.
+            if (app.getInvariantDeviceProfile().isSplitDisplay) {
+                screensToExclude.add(SECOND_SCREEN_ID);
+            }
         }
 
         for (int screen = 0; screen < screenCount; screen++) {