Cannot set custom StartDragDistance in QEglFSIntegration::styleHint

A custom StartDragDistance in QEglFSIntegration::styleHint is not used by the higher layers (QStyleHints, and higher up e.g. Flickable).

Looking at the code, this looks to be due to this being a "themeableHint" in QStyleHints. With the current implementation, the theme is always queried first. There is no custom theme, so QPlatformTheme::themeHint() is used, which queries QPlatformTheme::defaultThemeHint(), which returns a value of 10 (and the platform integration is never queried).

This looks like it would be a problem for other themableHints as well.