[Android] ArgumentOutOfRangeException Occurs with KeepLastItemInView for Grouped List

### Description

When using KeepLastItemInView in a CollectionView with a grouped list , an ArgumentOutOfRangeException is thrown. This issue occurs when adding a new item from top.

### Steps to Reproduce

1. Run the attached sample [ItemsUpdatingScrollModeIssue 3.zip](https://github.com/user-attachments/files/19869454/ItemsUpdatingScrollModeIssue.3.zip)
2. Select KeepLastItemInView and add new item observe that it throws an ArgumentOutOfRangeException.

Expected Behavior:

- The CollectionView should automatically scroll to the last item in the group without throwing an exception.

Actual Behavior:

- An ArgumentOutOfRangeException is thrown with the message: 'Index was out of range. Must be non-negative and less than the size of the collection.'

### Link to public reproduction project repository

_No response_

### Version with bug

9.0.60 SR6

### Is this a regression from previous behavior?

Not sure, did not test other versions

### Last version that worked well

_No response_

### Affected platforms

Android

### Affected platform versions

_No response_

### Did you find any workaround?

_No response_

### Relevant log output

```shell

```

Start by running the attached ItemsUpdatingScrollModeIssue 3.zip sample on Android and reproduce the exception with KeepLastItemInView, a grouped CollectionView, and an item added from the top. Trace the grouped-list update and scrolling path; done means adding the item scrolls to the last item in its group without an ArgumentOutOfRangeException.

Written by the indexing model from the issue text.