Optimizes the WindowBackdrop Settings before version 22H1

[MakesYT]

Optimizes the WindowBackdrop Settings before version 22H1,Thus automatically switches to a supported effect instead of an error in earlier versions
Sets the IconSourceElementConverter to public, sometimes need to use this converter

Pull request type

Please check the type of change your PR introduces:

• Update
• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes

What is the current behavior?

If the WindowBackdrop type Acrylic is not supported in an early version, it will fail and throw error.
Can,t use IconSourceElementConverter

Issue Number: N/A

What is the new behavior?

• automatically switches to a supported effect instead of an error in earlier versions

Other information

[cla-bot]

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