Update heap default to include unit and drop wrapper.conf
Update heap default to include unit and drop wrapper.conf

This [PR](https://github.com/neo4j/neo4j/pull/8138) enables the use of
units in heap config.

`neo4j-wrapper.conf` is deprecated so no reason to use it.

neo4j/docker-neo4j,neo4j/docker-neo4j,neo4j-contrib/docker-neo4j,neo4j-contrib/docker-neo4j