[iOS, Border] Border with a inner image doesn't animate right

### Description

On iOS, when I have an image inside a border and make it rounded and animate it part of the image disappears.


### Steps to Reproduce

Run the linked project

### Link to public reproduction project repository

https://github.com/pictos/borderanimationbug

### Version with bug

9.0.40 SR4

### Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

### Last version that worked well

9.0.0 GA

### Affected platforms

iOS

### Affected platform versions

_No response_

### Did you find any workaround?

No

### Relevant log output

```shell

```

Start by running the linked reproduction project at https://github.com/pictos/borderanimationbug on iOS and compare behavior between .NET MAUI 9.0.40 SR4 and 9.0.0 GA. Trace the border, image, and rounded-corner animation behavior exposed by the reproduction; done means the full image remains visible while the rounded border animates.

Written by the indexing model from the issue text.