fix: use defaultValue in field control

Co-authored-by: Alex Lykesas <[email protected]>

packages/admin/components/fields/field-control.tsx

@@ -77,7 +77,7 @@ export const FieldControl = ( {
 	onChange,
 	required,
 	type,
-	value,
+	value: originalValue,
 	...rest
 }: FieldControlProps ) => {
 	const controlType =
@@ -93,6 +93,9 @@ export const FieldControl = ( {
 		return null;
 	}
 
+	// Fallback to the default value if the value is not set.
+	const value = originalValue ?? rest?.default;
+
 	// Build the component props.
 	let componentProps: ControlComponentPropsMap[ typeof controlType ] = {
 		label: label || description,