test(bazel): Use local_repository to load Angular (#28142)

The current integration test for Bazel schematics downloads a
published version of Angular as required by the http_archive
rule in the CLI created WORKSPACE.
However, this makes the test less useful because it does not
actually test any changes to the Angular repo at source.
This PR replaces the http_archive method in the WORSPACE
with local_repository so that any local changes to the Angular
repo are tested accordingly.

With Typescript 3.2, the file e2e/src/app.po.ts generated by CLI
no longer compiles under Bazel due to missing type annotations.
A temporary file is placed in the integration/bazel-schematics
directory while the change is pending in CLI repo.
https://github.com/angular/angular-cli/pull/13406

PR Close #28142

integration/bazel-schematics/test.sh

@@ -8,7 +8,11 @@ function testBazel() {
   rm -rf demo
   # Create project
   ng new demo --collection=@angular/bazel --defaults --skip-git
+  node replace_angular_repo.js "./demo/WORKSPACE"
   cd demo
+  # TODO(kyliau) Remove this once the type annotations are added to AppPage
+  # https://github.com/angular/angular-cli/pull/13406
+  cp ../app.po.ts ./e2e/src/
   # Run build
   # TODO(kyliau): Use `bazel build` for now. Running `ng build` requires
   # node_modules to be available in project directory.