Frozen indices (partial searchable snapshots) require less heap per
shard and the limit can therefore be raised for those. We pick 3000
frozen shards per frozen data node, since we think 2000 is reasonable
to use in production.

Relates elastic#71042 and elastic#34021

If master ends up on a newer version than other cluster members, we
cannot apply the new index setting for shard limits. We skip doing so
for now.