Change HDFS settings to easily allow Accumulo init

[GCHQDeveloper314]

In all docker-compose.yaml files that involve Accumulo, there's this comment on each Accumulo service:

https://github.com/gchq/gaffer-docker/blob/61df0181fb0ce2eab02b8b72dd3bd59cce6708dc/docker/gaffer/docker-compose.yaml#L82-L86

For Kubernetes the following is done to grant "the right permissions":

https://github.com/gchq/gaffer-docker/blob/61df0181fb0ce2eab02b8b72dd3bd59cce6708dc/kubernetes/accumulo/values.yaml#L29-L32

The claim that this cannot be done in docker-compose doesn't seem to be correct. It should be possible to run the same commands in the HDFS container when using docker-compose.

However, seeing as secure mode is not in use and the only client is Accumulo, there's very little point in using HDFS permissions. Disabling them (by setting dfs.permissions.enabled to false) removes the need for this workaround and this tedious repeating comment in many docker-compose.yaml files.