[iOS] Fixed a crash in CarouselViewHandler2 on iOS 15.

[Ahamed-Ali]

Root Cause of the issue

• The crash in iOS 15 versions is likely due to the use of API methods that are not available in iOS 15 and earlier. The GetHorizontalGroup and GetVerticalGroup methods used in the SelectLayout override method of CarouselViewHandler2.iOS were introduced iniOS 16.0.

Description of Change

• Fixed the crash by using compatible API methods based on the iOS version.

Issues Fixed

Fixes #27818

Tested the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Tested Version

iOS Version	App Crashed
15.2	Yes
15.5	Yes
16.0	No
17.5	No
18.0	No
18.2	No

Screenshot

iOS 15.2 and 15.5

Before Issue Fix	After Issue Fix
iOS15.2Fix.mov	iOS15.2Issue.mov
iOS15.5Issue.mov	iOS15.5fix.mov

iOS 16.0

iOS16.0.mov

iOS 17.5

17.5.mov

iOS 18.2

iOS18.2.mov

[dotnet-policy-service]

Hey there @Ahamed-Ali! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[jsuarezruiz]

/azp run

[azure-pipelines]

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[Copilot]

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

src/Controls/src/Core/Handlers/Items2/CarouselViewHandler2.iOS.cs:49

• [nitpick] Consider initializing the 'group' variable at the point of declaration for better readability.

NSCollectionLayoutGroup group = null;