Stabilize connectivity API methods on ClientConn

[GTB3NW]

The godoc on WaitForStateChange (https://github.com/grpc/grpc-go/blame/13b378bc458535e6da1693fc67e09a4951cd3259/clientconn.go#L503) is unchanged in 5 years. Is this still considered experimental by the maintainers or can I PR to remove this notice?

[easwars]

Are you planning on using this API? Or are you already using it? Do you have any feedback about this API?

We haven't received enough feedback on this API to come to a conclusion on whether to remove the experimental label.

[GTB3NW]

Are you planning on using this API?

I am indeed - see #5498 for a concern I have atm

Or are you already using it?

Just running some experiments myself at the moment to see whether the above is viable. I started with the understanding the connectivity API was implemented to spec but have come to realise it's not.

Do you have any feedback about this API?

I'll update this issue with time. At the moment the api looks good, I'd maybe be interested in expanding the arguments to allow for multiple states to watch for changes from, but that would be backwards compatible with the current design.

We haven't received enough feedback on this API to come to a conclusion on whether to remove the experimental label.

Understandable! Hopefully I can assist :)

[github-actions]

This issue is labeled as requiring an update from the reporter, and no update has been received after 6 days. If no update is provided in the next 7 days, this issue will be automatically closed.