[release/8.0][Apple] Use NSLocale.preferredLanguages on for default locale name

[matouskozak]

Description

In this PR, we change the DetectDefaultAppleLocaleName to use the ObjC preferredLanguages API to retrieve the device's primary language. This will make sure that users can retrieve the correct locale and use localized strings as expected.

Note, this doesn't change the specific whitelisting done for mobile .NET 8 ICU https://github.com/dotnet/icu/blob/dotnet/main/icu-filters/icudt_mobile.json#L8-L194. Users will be able retrieve the underlining ICU data (e.g. DateTimeFormat) only for the locales specifically included the ICU pack.

Customer Impact

• Customer reported Ios Maui sample app uses Chinese Simplified when Chinese Traditional is set in phone preferences #102560
• Found internally

Customer reported incorrect locale returned when setting iPhone region to "China mainland" and language to "Chinese Traditional". Returned zh-CN instead of zh-Hant-CN.

Regression

• Yes
• No

Testing

Tested locally on iOS simulator by copying new libSystem.Globalization.Native.dylib and libmonosgen-2.0.dylib into a local version of dotnet and building customer provided MAUI repro app. Verified that the MAUI repro works as expected with the fix included in this PR.

Risk

Affects Globalization code on Apple mobile scenario.

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[matouskozak]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[carlossanlop]

Today is code complete for the July Release. Has this been approved by Tactics? Can you please get a code review sign-off from the area owners?

[carlossanlop]

There's also many CI failures. Can you please check if they're related to this PR?

[matouskozak]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[matouskozak]

There's also many CI failures. Can you please check if they're related to this PR?

The failures on runtime-extra-platforms CI are un-related and already present on the other release/8.0-staging runs (e.g. https://dev.azure.com/dnceng-public/public/_build/results?buildId=703219)