CacheMetrics update and rolling upgrades.

[Pavel Pereslegin]

Hi, Igniters!

I’m working on IGNITE-6333 [1] and I need to add two new metrics into
CacheMetrics.
As I see, versioning is not supported for now.
Do I need to care about rolling upgrades?

[1] https://issues.apache.org/jira/browse/IGNITE-6333