Fix more instances of JSON schema getting clobbered when attaching references (#15339)

This PR extends the fix from #15336 to more places that had the same
issue.

An `add_references_to_properties` helper function has been added to
handle these cases uniformly.

Release Notes:

- N/A

crates/settings/src/json_schema.rs

@@ -0,0 +1,36 @@
+use schemars::schema::{RootSchema, Schema};
+
+type PropertyName<'a> = &'a str;
+type ReferencePath<'a> = &'a str;
+
+/// Modifies the provided [`RootSchema`] by adding references to all of the specified properties.
+///
+/// # Examples
+///
+/// ```
+/// # let root_schema = RootSchema::default();
+/// add_references_to_properties(&mut root_schema, &[
+///     ("property_a", "#/definitions/DefinitionA"),
+///     ("property_b", "#/definitions/DefinitionB"),
+/// ])
+/// ```
+pub fn add_references_to_properties(
+    root_schema: &mut RootSchema,
+    properties_with_references: &[(PropertyName, ReferencePath)],
+) {
+    for (property, definition) in properties_with_references {
+        let Some(schema) = root_schema.schema.object().properties.get_mut(*property) else {
+            log::warn!("property '{property}' not found in JSON schema");
+            continue;
+        };
+
+        match schema {
+            Schema::Object(schema) => {
+                schema.reference = Some(definition.to_string());
+            }
+            Schema::Bool(_) => {
+                // Boolean schemas can't have references.
+            }
+        }
+    }
+}