prechecks doesn't pick up no timezone set

[Oliver Kelly]

When running the kolla-ansible deploy, it will get to restart fluentd and restart kolla-toolbox and fail.

Turns out, the nodes we were deploying on had no set timezones. This should be picked up by the prechecks, it checks that `/etclocaltime` exists but in our env, it symlinked to `/usr/share/zoneinfo/string` instead of `/usr/share/zoneinfo/Europe/London` for example.

This caused the fluentd and kolla-toolbox containers to fail to start, when trying to start the container manually `docker start kolla-toolbox` would get the following error:

```
root@node1: ~# docker start kolla_toolbox
Error response from daemon: error while creating mount source path '/etc/localtime': mkdir /etc/localtime: file exists
Error: failed to start containers: kolla_toolbox
```

**Environment**:
* OS (e.g. from /etc/os-release): Debian GNU/Linux 12 (bookworm)
* Kernel (e.g. `uname -a`): 6.1.0-21-amd64
* Docker version if applicable (e.g. `docker version`): Docker version 26.1.4, build 5650f9b
* Kolla-Ansible version (e.g. `git head or tag or stable branch` or pip package version if using release): stable/2024.1
* Are you using official images from Docker Hub or self built? Official
* Share your inventory file, globals.yml and other configuration files if relevant