docs: clarify hierarchical injectors (#28700)

PR Close #28700

aio/content/examples/resolution-modifiers/e2e/src/app.e2e-spec.ts

@@ -0,0 +1,21 @@
+import { browser, element, by } from 'protractor';
+
+describe('Resolution-modifiers-example', function () {
+
+  beforeAll(function () {
+    browser.get('');
+  });
+
+  it('shows basic flower emoji', function() {
+    expect(element.all(by.css('p')).get(0).getText()).toContain('🌸');
+  });
+
+  it('shows basic leaf emoji', function() {
+    expect(element.all(by.css('p')).get(1).getText()).toContain('🌿');
+  });
+
+  it('shows yellow flower in host child', function() {
+    expect(element.all(by.css('p')).get(9).getText()).toContain('🌼');
+  });
+
+});