run_check_repl_oplog.js is a hook called from resmoke with a function runCheckOnReplSet that calls db.isMaster().  In a serverless environment, if the featureFlagRequireTenantID is set we need a tenantId to pass into the command (if not issued against admin, local, or config), and we should either use $tenant or be creating a security token connection in order to query with a tenantId.