Automatic merge from submit-queue (batch tested with PRs 43355, 42827) [Federation] Rewrite ReplicaSet CRUD and Preferences tests. I think `should create replicasets and rebalance them` test is still flaky. I still don't know the source of this flakiness. I will continue hunting. But it is a lot less flaky than before (or perhaps it even never passed before?). This PR could be merged now and flake hunting can happen in parallel. ```release-note NONE ```