[robustness tests] Add leases to Kubernetes traffic generator #20621
Description
What would you like to be added?
Kubernetes traffic generator should use LeaseGrant and then use ID in calls to OptimisticPut. This pattern should mimic what apiserver does for masterleases (maintaining one object per apiserver for fault detection) or events (expiring groups of ~75 objects).
As TTL is not supported, traffic generator could call LeaseRevoke after some time (real apiserver relies on TTL and never revokes leases).