Relative imports in Typescript files only work when module_name is
defined in ts_library (when run in Node.js).
See issue https://github.com/bazelbuild/rules_typescript/issues/360
With that fixed, `ng test` now works.
`ng build` requires `node_modules` to be available in the project
directory, so it's not usable yet. Running `yarn` in project directory
does not work because of postinstall version check.
PR Close#27715