Remove privileged mode requirement

[siegfriedweber]

Description

Remove the requirement for privileged mode.

The SELinux options still have to be quite privileged to allow the listener-operator to write into the volumes in other namespaces.

Closes #70

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [x] Changes are OpenShift compatible
- [x] CRD changes approved
- [x] Helm chart can be installed and deployed operator works
- [x] Integration tests passed (for non trivial changes)

# Reviewer
- [x] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [x] Changelog updated
- [x] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added

[razvan]

First installation attempt failed on OpenShift 4.12:

helm upgrade listener-operator listener-operator --install --namespace stackable-operators --version 0.0.0-pr101 --wait  --devel --repo https://repo.stackable.tech/repository/helm-test

Event message:

Error creating: pods "listener-operator-controller-deployment-6df677f8df-" is forbidden: unable to validate against any security context constraint: [provider "anyuid": Forbidden: not usable by user or serviceaccount, provider "pipelines-scc": Forbidden: not usable by user or serviceaccount, provider "pipelines-custom-scc": Forbidden: not usable by user or serviceaccount, provider restricted-v2: .containers[0].runAsUser: Invalid value: 0: must be in the ranges: [1000710000, 1000719999], provider restricted: .containers[0].runAsUser: Invalid value: 0: must be in the ranges: [1000710000, 1000719999], provider "nonroot-v2": Forbidden: not usable by user or serviceaccount, provider "nonroot": Forbidden: not usable by user or serviceaccount, provider "hostmount-anyuid": Forbidden: not usable by user or serviceaccount, provider "zookeeper-scc": Forbidden: not usable by user or serviceaccount, provider "hbase-scc": Forbidden: not usable by user or serviceaccount, provider "hdfs-scc": Forbidden: not usable by user or serviceaccount, provider "machine-api-termination-handler": Forbidden: not usable by user or serviceaccount, provider "hostnetwork-v2": Forbidden: not usable by user or serviceaccount, provider "hostnetwork": Forbidden: not usable by user or serviceaccount, provider "hostaccess": Forbidden: not usable by user or serviceaccount, provider "node-exporter": Forbidden: not usable by user or serviceaccount, provider "privileged": Forbidden: not usable by user or serviceaccount, provider "privileged-genevalogging": Forbidden: not usable by user or serviceaccount]

[razvan]

Sorry for the formatting. The relevant part is this:

.containers[0].runAsUser: Invalid value: 0: must be in the ranges: [1000710000, 1000719999]

[siegfriedweber]

https://ci.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/listener-operator-it-custom/3/