[Fleet] UI for opt-in into space awareness

[nchaulet]

Description

#189387 PR will make space awareness opt-in via an API, we should expose this in the UI

The opt-in UI should live in the advanced section of the Fleet settings and only accessible to an admin operator (with All privileges for agents, agent policies and settings)

API to opt in

POST /internal/fleet/enable_space_awareness

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[cmacknz]

Where did we land on making this the default for new deployments so that we have a path to not needing this migration long term?

[nchaulet]

Where did we land on making this the default for new deployments so that we have a path to not needing this migration long term?

It's not done yet, I will create a follow up issue for that. Does this will be achievable before 9.0? It seems to me having that new behaviour is kind of a breaking change has a user that want to create a new deployment for a new region/testing environment will have a different behaviour that what they expect

[cmacknz]

This is definitely something we should consider for 9.0. If we made this the default mode in 9.0 that would require very user to go through this migration to get to 9.0.