In Aura, we currently do not support changing any property that may exist in the Neo4j product and defined in neo4j.conf.
Instead, our instances have all the settings for security, networking, clustering, logging, and memory resources all predefined for optimal security, performance and availability in Aura.
In rare cases, a customization may be possible. Please contact support and raise a ticket.
You may also submit an improvement at https://neo4j-aura.canny.io/