storage: de-flake (again) TestReplicaLeaseCounters
storage: de-flake (again) TestReplicaLeaseCounters

My attempt at outsmarting replay protection was futile. Instead, assert
that which can actually be asserted.

Fixes #6441.

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