[Functions] stop using `reservedInstanceCount` and use `preWarmedInstanceCount`

[ahmedelnably]

stop using reservedInstanceCount and use preWarmedInstanceCount

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @ ahmedelnably, @fabiocav

[dariagrigoriu]

Will update once the latest SDK is available (PR pending).

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @ahmedelnably, @fabiocav

[fabiocav]

@panchagnula can you confirm that we have an updated SDK with the new property now?

Also need to confirm that making this change wouldn't be breaking.

[panchagnula]

yes the SDK is updated & released.