Limit the number of concurrent notifs appear on screen

To avoid an ANR in notification history

Test: Manual; with an app with 10k recent notifications
Bug: 183712803
Change-Id: Ia1340accadf43620c7b5a2c94ca1032cfe49ea59

src/com/android/settings/notification/history/NotificationHistoryAdapter.java

@@ -71,6 +71,11 @@ public class NotificationHistoryAdapter extends
         return new NotificationHistoryViewHolder(view);
     }
 
+    @Override
+    public long getItemId(int position) {
+        return mValues.get(position).hashCode();
+    }
+
     @Override
     public void onBindViewHolder(final @NonNull NotificationHistoryViewHolder holder,
             int position) {

src/com/android/settings/notification/history/NotificationHistoryRecyclerView.java

@@ -40,7 +40,6 @@ public class NotificationHistoryRecyclerView extends RecyclerView {
         ItemTouchHelper touchHelper = new ItemTouchHelper(
                 new DismissTouchHelper(0, ItemTouchHelper.START | ItemTouchHelper.END));
         touchHelper.attachToRecyclerView(this);
-        setNestedScrollingEnabled(false);
     }
 
     public void setOnItemSwipeDeleteListener(OnItemSwipeDeleteListener listener) {