Default state for type, then if there is host-catalog as parent, inherit its type

addons/api/mirage/factories/host-set.js

@@ -12,6 +12,11 @@ export default factory.extend({
       'remove-hosts',
     ],
   id: (i) => `host-set-id-${i}`,
+  type() {
+    if (this.hostCatalog) {
+      return this.hostCatalog.type;
+    }
+  },
   plugin() {
     if (this.type === 'plugin') {
       return this.hostCatalog.plugin;

addons/api/mirage/generated/factories/host-set.js

@@ -5,7 +5,7 @@ import { random, date, datatype } from 'faker';
  * GeneratedHostSetModelFactory
  */
 export default Factory.extend({
-  type: () => this.hostCatalog.type,
+  type: 'static',
   name: () => random.words(),
   description: () => random.words(),
   created_time: () => date.recent(),