Fix continuous create and delete of cluster roles and bindings

[davidor]

What does this PR do?

When external metrics are enabled in the cluster agent, the datadog-cluster-agent-metrics-reader cluster role and the datadog-cluster-agent-metrics-reader and datadog-cluster-agent-auth-delegator cluster role bindings are being created and deleted continuously.

This PR fixes the bug. There were 2 issues, each solved in one commit:

1. The functions that manage cluster roles and cluster role bindings were not handling correctly the "cleanup" case. In that case, they were creating the resource, and then deleting it.
2. The controller was setting the cleanup attr incorrectly. The cluster roles and bindings mentioned above should be created when external metrics are enabled, but the controller was doing the opposite.

Describe your test plan

Enable external metrics in the cluster agent:

  clusterAgent:
    config:
      externalMetrics:
        enabled: true

Check that the cluster roles and cluster role bindings mentioned above are not created and deleted continuously.

[github-actions]

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[codecov-commenter]

Codecov Report

Merging #441 (e903fac) into main (f267051) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #441   +/-   ##
=======================================
  Coverage   61.05%   61.05%           
=======================================
  Files           3        3           
  Lines          95       95           
=======================================
  Hits           58       58           
  Misses         25       25           
  Partials       12       12           

Flag	Coverage Δ
unittests	61.05% <ø> (ø)

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