fix: ResourceLoaderStringLocalizer not resolving

[Xiaoy312]

GitHub Issue (If applicable): closes unoplatform/uno#16627

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

IStringLocalizer not resolving on non-windows platforms

What is the new behavior?

^ fixed

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Docs have been added/updated which fit documentation template. (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Wasm UI Tests are not showing unexpected any differences. Validate PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Updated the Release Notes
• Associated with an issue (GitHub or internal)

Other information

the null-coalesce is working poorly on these two

[agneszitte]

@nickrandolph, @Xiaoy312 I think this change should be backported no?

[jeromelaban]

@Mergifyio backport release/stable/4.1

[mergify]

backport release/stable/4.1

✅ Backports have been created

• #2305 fix: ResourceLoaderStringLocalizer not resolving (backport #2302) has been created for branch release/stable/4.1