chore: set readOnlyRootFilesystem on Operator Container

[coreydaley]

Description

Sets the readOnlyRootFilesystem option for the container securityContext to true.

Which issue(s) does this PR fix or relate to

https://issues.redhat.com/browse/RHIDP-5762

PR acceptance criteria

• Tests
• Documentation

How to test changes / Special notes to the reviewer

[openshift-ci]

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[github-actions]

⚠️ Files changed in bundle generation!

Those changes to the operator bundle manifests should have been pushed automatically to your PR branch.

[github-actions]

PR images are available:

1. https://quay.io/rhdh-community/operator:0.5.0-pr-740-9873ca7
2. https://quay.io/rhdh-community/operator-bundle:0.5.0-pr-740-9873ca7
3. https://quay.io/rhdh-community/operator-catalog:0.5.0-pr-740-9873ca7

[github-actions]

PR images are available:

1. https://quay.io/rhdh-community/operator:0.5.0-pr-740-cfeb712
2. https://quay.io/rhdh-community/operator-bundle:0.5.0-pr-740-cfeb712
3. https://quay.io/rhdh-community/operator-catalog:0.5.0-pr-740-cfeb712

[coreydaley]

@rm3l @gazarenkov ptal