document type editor shows linkpicker.base.uuid and linkpicker.language.context.aware properties but these cannot be saved

To reproduce:

• Start a new project
• Create a new document type
• Add a rich text area
• Enter a value for either linkpicker.base.uuid or linkpicker.language.context.aware properties
• Leave the field

Expected: the value remains and can be saved
Actual: the value is cleared