Update InAppNotification style to match WinUI InfoBar

[michael-hawker]

Fixes #3770

Rebase of PR from #3771 to not submit from main branch of fork. Also adjusts DPI scaling height of buttons from 30 to 32.

Will just merge, as PR was signed-off already, this is just a rebase to avoid potential problems from submitting main to main.

FYI @ismaelestalayo - More info in Wiki

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Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
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• Sample in sample app has been added / updated (for bug fixes / features)
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• Contains NO breaking changes

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[ghost]

Thanks michael-hawker for opening a Pull Request! The reviewers will test the PR and highlight if there is any conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌