Use the number of shown hotseat icons instead of database items to store into the DB

It seems this issue was originated from ag/14129534 and we should no
longer use numDatabaseHotseatIcons form IDP and use numShownHotseatIcons
from the DP.

Fix: 305119735
Flag: NA
Test: manuall testing, we don't have this test for landscape
Change-Id: Ie530748f9b77d89ac3298c187ae767643d505cb3

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

@@ -101,8 +101,7 @@ public abstract class BaseModelUpdateTask implements ModelUpdateTask {
     public ModelWriter getModelWriter() {
         // Updates from model task, do not deal with icon position in hotseat. Also no need to
         // verify changes as the ModelTasks always push the changes to callbacks
-        return mModel.getWriter(false /* hasVerticalHotseat */, false /* verifyChanges */,
-                CellPosMapper.DEFAULT, null);
+        return mModel.getWriter(false /* verifyChanges */, CellPosMapper.DEFAULT, null);
     }
 
     public void bindUpdatedWorkspaceItems(@NonNull final List<WorkspaceItemInfo> allUpdates) {