InterfaceCodeGenerator wraps @DBusBoundProperty type parameter in quotes

[zugaldia]

When generating interfaces with @DBusBoundProperty annotations that include a type parameter, the code generator produces a string literal instead of a class reference:

// Generated
@DBusBoundProperty(type = "PropertySupportedOptionsType.class")                                                                                 

Instead of:

// Expected                                                                                                                                     
@DBusBoundProperty(type = PropertySupportedOptionsType.class)                                                                                   

This causes a compilation error since type expects Class<?>, not String.

Reproduced with 6.0.0-SNAPSHOT generating from the org.freedesktop.portal.Notification XML definition. PR demonstrating this change in downstream project: zugaldia/stargate#20. Workaround in this commit: zugaldia/stargate@457ed25

[hypfvieh]

I added a small patch to fix this issue.