[net7.0] Ensure that Grid is treating star rows/columns as Auto when unconstrained

[github-actions]

Backport of #13999 to net7.0

/cc @PureWeen @hartez

[PureWeen]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[mikebikerider]

The #14165 'Ensure that Grid is treating star rows/columns as Auto when unconstrained' brakes existing grid layouts for iOS.
When a grid has a star Height row and 'auto' rows beneath it, and I place into the star row a vertical layout CollectionView or a ListView the control will push any visible control in rows below off the visible screen, UseSafeArea ignored.

If I click the Hide button to hide the control (CollectionView) the Label and button beneath the CollectionView appear at the correct position with the iOS Save Area.

I can toggle the Collection IsVisible back to true using the same button and the CollectionView will push the Label with text out of the Safe Area and off the visible portion of the screen.

I could not find which MAUI controls are officially 'unconstrained'. A map control placed into a star height row also pushes down controls in auto height rows beneath it.

If change the 'star' row to 'auto' in VS2022 Hot Reload the iOS screen does not change. In the below iOS iPhone 14 Pro simulator screenshot the CollectionView has two items and still pushes the controls below it off screen.

The same code with the Collection View in the 'auto' height row running in the Google Pixel 5 simulator.

Android CollectionView (Windows too) exhibits constraint. If it has 2 rows it will occupy space for 2 rows and will resize when more added, or some removed. iOS CollectionView is a different beast. I am aware of it.

In my Xamarin apps I have CollectionView controls in 'star' and in 'auto' rows, depending on the context. Handling a CollectionView in a grid 'auto' row can be tricky. My code must calculate the HeightRequest. This works well if there is a star row in the grid that can shrink or expand. It works great in Xamarin. In MAUI it depends what kind of control is in the star row and how well or not MAUI GridLayoutManager handles the 'star' row content. If I place a map control into the star grid row in MAUI iOS app and I have a CollectionView in the 'auto' grid row below the map, it was already not handled gracefully prior to #14165. After I upgraded VS2022 to 17.6.2 it got worse. Now in addition to the CollectionView not always rendered at a correct position the lower grid row is cut off at the bottom of the screen. I didn't have these issues when using Xamarin.Forms. The last MAUI update forced me to put a transition to MAUI project on hold. Not that I am much upset about that. The Xamarin app I was moving runs faster than the MAUI version, screen refresh cleaner.

I suggest restoring previous functionality where star rows are treated as star rows.

[mikebikerider]

Besides grids, map control fell victim to #14165 'treating star rows as auto' under iOS.

The page layout is a grid, the top 'star' row has a map control, the bottom 'auto' row has a grid with navigation buttons.
Whan the page loads in the simulator it looks fine. I rotate the page to landscape and the bottom bar is pushed down beyond the safe area.

A click on the info button shows a label with the copyright notice. The label is in an 'auto' row initially hidden.

When the row with the copyright label became visible it pushed down the bottom navigation bar instead of pushing up the map lower border.
That is not how it should look and did look prior to #14165

I made the page look as it should by setting map MaximumHeighRequest to 0.

<Map x:Name="map" Grid.Row="0" MaximumHeightRequest="0"/>

This silly trick doesn't work well for grids.
This #14165 update came out terribly wrong.