Group membership update due to static member rejoin should be persisted

For known static members rejoin, we would update its corresponding member.id without triggering a new rebalance. This serves the purpose for avoiding unnecessary rebalance for static membership, as well as fencing purpose if some still uses the old member.id. 

The bug is that we don't actually persist the membership update, so if no upcoming rebalance gets triggered, this new member.id information will get lost during group coordinator immigration, thus bringing up the zombie member identity.

The bug find credit goes to Jason Gustafson