Use the same location for messages.log regardless of tracing enabled or not

[leochr]

The location of the messages.log changes depending on whether Day-2 operation trace is enabled or not. By default it's written to /logs, but it changes to /serviceability/<namespace>/<pod_name> when trace operation is enabled. It's not possible to configure Liberty server to use one location for messages.log and another location for trace files. It's all controlled by logDirectory` value in server.xml.

Use the same location to store messages.log. One suggestion is to symlink the default location /logs to the serviceability location at container startup via the Liberty Operator (if serviceability is enabled)

Additional discussion in this internal thread: https://ibm-cloud.slack.com/archives/C020VHDP0M8/p1738179825766089