fix(@angular-devkit/core): improve handling of set schema values

Closes #20594

(cherry picked from commit 09676c9)

Author: alan-agius4

packages/angular_devkit/core/src/json/schema/registry.ts

@@ -558,7 +558,7 @@ export class CoreSchemaRegistry implements SchemaRegistry {
       CoreSchemaRegistry._set(
         data,
         pathFragments,
-        answers[path] as {},
+        answers[path],
         null,
         undefined,
         true,
@@ -567,51 +567,22 @@ export class CoreSchemaRegistry implements SchemaRegistry {
   }
 
   private static _set(
-    // tslint:disable-next-line:no-any
+    // tslint:disable-next-line: no-any
     data: any,
     fragments: string[],
-    value: {},
-    // tslint:disable-next-line:no-any
-    parent: any | null = null,
+    value: unknown,
+    parent: Record<string, unknown> | null = null,
     parentProperty?: string,
     force?: boolean,
   ): void {
-    for (let i = 0; i < fragments.length; i++) {
-      const f = fragments[i];
-
-      if (f[0] == 'i') {
-        if (!Array.isArray(data)) {
-          return;
-        }
-
-        for (let j = 0; j < data.length; j++) {
-          CoreSchemaRegistry._set(data[j], fragments.slice(i + 1), value, data, '' + j);
-        }
-
-        return;
-      }
-
-      if (f.startsWith('key')) {
-        if (typeof data !== 'object') {
-          return;
-        }
-
-        for (const property in data) {
-          CoreSchemaRegistry._set(data[property], fragments.slice(i + 1), value, data, property);
-        }
-
-        return;
-      }
-
-
-      // We know we need an object because the fragment is a property key.
+    for (const fragment of fragments) {
       if (!data && parent !== null && parentProperty) {
         data = parent[parentProperty] = {};
       }
-      parent = data;
-      parentProperty = f;
 
-      data = data[f];
+      parent = data;
+      parentProperty = fragment;
+      data = data[fragment];
     }
 
     if (parent && parentProperty && (force || parent[parentProperty] === undefined)) {