Add system test for validating static consumer bounce and assignment when not eager

Existing system test include a test for validating that partitions are not re-assigned when a static member is bounced, but the test design and setup is intended for testing this for the Eager assignment strategy only (based on the eager protocol where all dynamic members revoke their partitions when a rebalance happens).
We should considering adding a test that would ensure that partitions are not re-assigned when using the cooperative sticky assignor or the new consumer group protocol assignments.