Backport of Set ReadOnlyRootFilesystem and AllowPrivilegeEscalation to false into release/1.2.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #3498 to be assessed for backporting due to the inclusion of the label backport/1.2.x.

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The person who merged in the original PR is:
@thisisnotashwin
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

merge conflict error: POST https://api.github.com/repos/hashicorp/consul-k8s/merges: 409 Merge conflict []

The below text is copied from the body of the original PR.

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Tighten up privileges for consul-dataplane and connect-init containers
when CNI is enabled.

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Overview of commits

• 3077563

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[thisisnotashwin]

Closed by #3512