amp-lightbox-gallery - unexpected behavior with thumbnails

### Description

When you click a thumbnail to open an [amp-lightbox-gallery](https://amp.dev/documentation/components/amp-lightbox-gallery/?format=websites), the first image in the gallery will show up, rather then the image associated with the clicked thumbnail.

Note that this was something we only recently discovered on one of our sites using amp-lightbox-gallery, and all our sites using amp-lightbox-galleries are affected.

This was discovered by a team member on the 21st of july, and have not been a problem in the past.

This issue is only present in v0.1 of the component, and seems to be fixed in v1.0

### Reproduction Steps

https://amp.dev/documentation/examples/e-commerce/hotel/preview/?format=websites

This is reproduceable in the hotel demo on amp.dev

if you click any image, it will scale up, and then switch to the first image in the gallery.

### Relevant Logs

_No response_

### Browser(s) Affected

Chrome, Firefox, Safari, Edge

### OS(s) Affected

_No response_

### Device(s) Affected

_No response_

### AMP Version Affected

_No response_