Describe the enhancement:

Currently, for the stack modules in Metricbeat, when xpack.enabled is set to true, we validate that certain metricsets are present in the configuration. If they are not, we display an error in the logs.

It would be much better if we simply configure those metricsets automatically (i.e. in code vs. requiring the user to configure them in the module configuration) if the user has set xpack.enabled: true in the module configuration.

Describe a specific use case for the enhancement or feature:

To easily configure the Metricbeat stack modules for stack monitoring.