amp-carousel index does not update on amp-form when an input is invalid on submit and autoslides

### Description

Hello, im developing an email with amp-form and amp-carousel to slide thro questions and when submit triggers the validation, the slider moves to the correct slide, but the "currentIndex"/"slideCange" dosent change/trigger.
Have a good day, and btw, amp is pretty cool ;)

### Reproduction Steps

At the example you can see 4 slider buttons and at slide 2/4 there is a required field.
You can see a slide counter (1 of 4) that changes when you slide manualy, but when the validation is triggered when you submit, the slide index, dosent change(and the slideChange never trigger), i readed that the slideChange event can be a pain, but i think the index would need to be updated.
Thanks for all and i leave here the example: [AMP4Email PlayGround Example](https://playground.amp.dev/?mode=Pixel+2&runtime=amp4email#share=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)

### Relevant Logs

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### Browser(s) Affected

_No response_

### OS(s) Affected

_No response_

### Device(s) Affected

_No response_

### AMP Version Affected

_No response_