Fix `<RouteAnnouncer/>` shouldn't announce initial path under strict mode and React 18 (#34338)
As the comment mentioned, React 18 with Strict Mode enabled might cause double invocation of lifecycle methods. This makes the `<RouteAnnouncer/>` being non-empty for the initial page, which is a bug (it should only announce page change whenever a navigation happens).
## Bug
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes by running `yarn lint`