message: build(common): mark locales files as side-effect-full
  Fixes
  PR Close
diff: {
  "description": "This directory contains UMD files which by its nature are not side-effect free. The parent package.json marks the whole @angular/common package as side-effect free, so if this directory is not excluded from that, build-optimizer will mark the contents as side-effect free and uglify will incorrectly remove all needed localization code.",
  - "sideEffects": false
  + "sideEffects": true
  }
  