build: do not apply zone.js legacy browser patches in unit tests

Updates our infrastructure to not apply the zone.js legacy browser
patches. We don't run Bazel tests in legacy browsers, and using
the evergreen patches would match with the default CLI project setup.

This ensures that we can better reproduce issues that would also
surface in CLI projects. Before this change, tests could behave
differently due to ZoneJS legacy patches. e.g. ZoneJS patches
`Object.defineProperty` in a way that makes properties _always_
configurable, while the actual ECMAScript default is `configurable:
false`. This meant that we couldn't catch: #19440.
in our unit tests. We should fix this by not applying these legacy
ZoneJS patches, and rather match with the default setup in CLI projects.

Whenever we run legacy browser tests with Bazel, we would now need to load
the legacy patches (as done with the CLI). We need to explore possible
solutions for this, but that is not a critical task right now (given
that we don't test legacy browsers with Bazel).

Author: devversion

tools/defaults.bzl

@@ -248,7 +248,16 @@ def ng_web_test_suite(deps = [], static_css = [], bootstrap = [], tags = [], **k
             "@io_bazel_rules_webtesting//browsers:firefox-local",
         ],
         bootstrap = [
-            "@npm//:node_modules/zone.js/dist/zone-testing-bundle.js",
+            # This matches the ZoneJS bundles used in default CLI projects. See:
+            # https://github.com/angular/angular-cli/blob/master/packages/schematics/angular/application/files/src/polyfills.ts.template#L58
+            # https://github.com/angular/angular-cli/blob/master/packages/schematics/angular/application/files/src/test.ts.template#L3
+            # Note `zone.js/dist/zone.js` is aliased in the CLI to point to the evergreen
+            # output that does not include legacy patches. See: https://github.com/angular/angular/issues/35157.
+            # TODO: Consider adding the legacy patches when testing Saucelabs/Browserstack with Bazel.
+            # CLI loads the legacy patches conditionally for ES5 legacy browsers. See:
+            # https://github.com/angular/angular-cli/blob/277bad3895cbce6de80aa10a05c349b10d9e09df/packages/angular_devkit/build_angular/src/angular-cli-files/models/webpack-configs/common.ts#L141
+            "@npm//:node_modules/zone.js/dist/zone-evergreen.js",
+            "@npm//:node_modules/zone.js/dist/zone-testing.js",
             "@npm//:node_modules/reflect-metadata/Reflect.js",
         ] + bootstrap,
         tags = ["native"] + tags,