storage/engine: tune max_bytes_for_level_base
storage/engine: tune max_bytes_for_level_base

Per RocksDB tuning guidelines, set `max_bytes_for_level_base` to the
estimated size of L0.

petermattis/cockroach,arjun4084346/cockroach,maxlang/cockroach,cockroachdb/cockroach,vivekmenezes/cockroach,vaibhavarora/cockroach,cockroachdb/cockroach,arjun4084346/cockroach,veteranlu/cockroach,maxlang/cockroach,glycerine/cockroach,sunya123/cockroach,vivekmenezes/cockroach,vaibhavarora/cockroach,maxlang/cockroach,paperstreet/cockroach,glycerine/cockroach,cockroachdb/cockroach,sunya123/cockroach,glycerine/cockroach,cockroachdb/cockroach,vivekmenezes/cockroach,petermattis/cockroach,arjun4084346/cockroach,cockroachdb/cockroach,paperstreet/cockroach,vivekmenezes/cockroach,petermattis/cockroach,petermattis/cockroach,arjun4084346/cockroach,glycerine/cockroach,cockroachdb/cockroach,arjun4084346/cockroach,glycerine/cockroach,petermattis/cockroach,glycerine/cockroach,vivekmenezes/cockroach,sunya123/cockroach,paperstreet/cockroach,cockroachdb/cockroach,glycerine/cockroach,veteranlu/cockroach,petermattis/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,vivekmenezes/cockroach,paperstreet/cockroach,cockroachdb/cockroach,sunya123/cockroach,arjun4084346/cockroach,paperstreet/cockroach,veteranlu/cockroach,sunya123/cockroach,sunya123/cockroach,petermattis/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,vivekmenezes/cockroach,paperstreet/cockroach,maxlang/cockroach,maxlang/cockroach,veteranlu/cockroach,arjun4084346/cockroach,paperstreet/cockroach,maxlang/cockroach,veteranlu/cockroach,veteranlu/cockroach,glycerine/cockroach,veteranlu/cockroach,sunya123/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,maxlang/cockroach,petermattis/cockroach,arjun4084346/cockroach,vivekmenezes/cockroach,maxlang/cockroach,sunya123/cockroach