fix(ivy): TestBed should use annotation for the last match rather than the first (#28195)

When we look for matching annotations in TestBed, we should always take the last
matching annotation. Otherwise, we will return superclass data for subclasses,
which would have unintended consequences like directives matching the wrong selectors.

PR Close #28195

packages/core/src/render3/metadata.ts

@@ -28,7 +28,7 @@ export function setClassMetadata(
     propDecorators: {[field: string]: any} | null): void {
   const clazz = type as TypeWithMetadata;
   if (decorators !== null) {
-    if (clazz.decorators !== undefined) {
+    if (clazz.hasOwnProperty('decorators') && clazz.decorators !== undefined) {
       clazz.decorators.push(...decorators);
     } else {
       clazz.decorators = decorators;