feat: 🎸 create storage policy (#2079)

* feat: 🎸 add storage policy

addons/api/addon/transforms/object.js

@@ -22,7 +22,7 @@ export default class ObjectTransform extends Transform {
    */
   serialize(deserialized) {
     if (!deserialized) {
-      return null;
+      return {};
     }
     return deserialized;
   }