Kibana API for selecting default pattern

[henrikno]

Describe the feature:
In #72360 we have an API for updating the index patterns in Kibana, but I didn't see a way to control which one is the default one.

Describe a specific use case for the feature:
We update the list of dashboards/index patterns programmatically, and it seems like the default pattern picked is either random, or first/last one. We'd like a way to control which one is the default deterministically (either a property when creating it, or a separate API).

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[mattkime]

@henrikno Are you doing this within Kibana or with the REST api?

[henrikno]

@mattkime: With the REST API. Currently we actually update .kibana indices directly, which we're trying to migrate away from.

[mattkime]

I spoke with @henrikno and he said they're setting up index patterns from a process outside of kibana, hence the REST API usage.