test: disambiguate e2e and perf spec files (#34753)

Currently, based on the file names it's not quite clear whether
a given `.spec.ts` file runs benchmark perf or benchmark e2e
functionality tests. To disambiguate these, we use new file
suffixs. i.e. `e2e-spec.ts` and `perf-spec.ts`.

PR Close #34753

modules/benchmarks/src/tree/tree_detect_changes.e2e-spec.ts

@@ -0,0 +1,19 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {$} from 'protractor';
+
+import {openTreeBenchmark} from './test_utils';
+
+describe('tree benchmark detect changes', () => {
+  it('should work for detectChanges', () => {
+    openTreeBenchmark();
+    $('#detectChanges').click();
+    expect($('#numberOfChecks').getText()).toContain('10');
+  });
+});