BUG Prevent SelectUploadField breaking AssetAdmin

If the DI instructions are followed as per the documentation then the injected field interferes with AssetAdmin by ignoring the current folder.

This fix ensures that if a custom template is included without the folder selector, then it behaves as though the folder selector is disabled.
This is so ugly... Can't we override stuff through configuration somehow? Like, add a "disable_for_templates" param?