Reduce default ILM logging at startup

[jakelandis]

When Elasticsearch starts up it is kinda noisy w.r.t. the ILM policies added by default :

[2021-12-06T17:12:10,403][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [ml-size-based-ilm-policy]
[2021-12-06T17:12:10,439][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [metrics]
[2021-12-06T17:12:10,464][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [logs]
[2021-12-06T17:12:10,488][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [synthetics]
[2021-12-06T17:12:10,510][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [watch-history-ilm-policy]
[2021-12-06T17:12:10,534][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [ilm-history-ilm-policy]
[2021-12-06T17:12:10,557][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [slm-history-ilm-policy]
[2021-12-06T17:12:10,579][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [.deprecation-indexing-ilm-policy]
[2021-12-06T17:12:10,603][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [link] adding index lifecycle policy [.fleet-actions-results-ilm-policy]

Most of this logging should be turned into a debug logging and ideally only print out 1 or 2 INFO messages that encompass the high level info.

related: #81356 and #81398

[elasticmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[DaveCTurner]

I do agree that these 9 lines at startup are a bit excessively noisy but I would rather we didn't drop the info about changes to ILM policies from the INFO level logs. They are sometimes invaluable in tracking what happened in support cases.

Could we batch these changes into a single update which results in a single log line? Could we enhance the startup lifecycle so that the stuff that users need to see is delayed until these things are complete?

[DaveCTurner]

(Kinda relates #77505 too)