Don't disable balancer during restores

PBM v2 already disables balancer during backups and operator disables it during restores. After discussing with we realized that operator shouldn’t disable it during restores, as:

1. For logical restores, balancer needs to be running to correctly distribute data to shards

2. For physical restores, balancers status is not very important as PBM removes all the data and restores it for all shards

We need to remove this balancer code from operator.