Tiled gallery: Gallery transform produces wrong layout

When transforming the core Gallery block to a Tiled Gallery, the layout is different from when the same Tiled Gallery is created directly.

## To reproduce

1. Create a _Gallery_ block with at least 3 images.
1. Create a _Tiled Gallery_ block with the same images.
1. Transform the _Gallery_ to a _Tiled Gallery_. Depending on the image ratios, the transformed block may be different from the new block.

Note that any action with causes the images to be re-rendered will fix the layout, like selecting an image in the block.

## Screens

Here are screenshots of two galleries, above is transformed from core _Gallery_ block, below is a directly created _Tiled Gallery_ block. They should be identical after transform, but are different.

### Frontend


### Editor


Spotted while debugging https://github.com/Automattic/jetpack/issues/11150

cc: @simison

Start in the block editor by reproducing the Gallery-to-Tiled Gallery transform with at least three images and compare it with a directly created Tiled Gallery using the same images. The issue names no implementation files or tests; done means both layouts are identical immediately after transformation, without requiring a later image rerender.

Written by the indexing model from the issue text.