Support running as nonroot - random uid/gid

[hishamanver]

Hi there,

Trying to install redis-stack on an openshift cluster but it is failing as openshift security policies enforce the container to run as nonroot, but also with a random uid and gid (taken from a pool determined by cluster admins)

Wondering if we can update the Dockerfile to support? The idea would be to make all redis files group readable/executable where necessary