Two new flags are added to `ng serve`:
- `--public-host` (aliased by `--live-reload-client): Specify the URL that the browser client will use.
- `--disable-host-check`: Don't verify connected clients are part of allowed hosts.
Setting `--disable-host-check` will output a warning:
```
WARNING Running a server with --disable-host-check is a security risk. See https://medium.com/webpack/webpack-dev-server-middleware-security-issues-1489d950874a for more information.
```
See #6070 for more context about this change.
Fix#6070