Fix bug in disable_ptrace action to allow sysctl to disable ptrace.

[dreambeyondorange]

Previously the setting for Ubuntu systems was not getting used due to a misalignment between the cookbook and cli. On the cli, node['cluster']['enable_efa'] was set to 'efa' in the dna.json file, but the cookbook assumed the parameter was set to 'compute'. This causes the disable_ptrace action if clause to be skipped. This page describes the use of sysctl https://manpages.ubuntu.com/manpages/bionic/man5/sysctl.conf.5.html This page describes the function of the ptrace_scope parameter https://www.kernel.org/doc/Documentation/security/Yama.txt Chef actually generates a config file in /etc/sysctl.d/ for the parameter that is changed so it should persist. https://docs.chef.io/resources/sysctl/

Tests

• Manual kitchen tests in develop

Checklist

• Make sure you are pointing to the right branch and add a label in the PR title (i.e. 2.x vs 3.x)
• Check all commits' messages are clear, describing what and why vs how.
• Make sure to have added unit tests or integration tests to cover the new/modified code.
• Check if documentation is impacted by this change.

Please review the guidelines for contributing and Pull Request Instructions.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #2313 (f5f0e5a) into release-3.6 (7c85f17) will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           release-3.6    #2313   +/-   ##
============================================
  Coverage        70.01%   70.01%           
============================================
  Files               13       13           
  Lines             1834     1834           
============================================
  Hits              1284     1284           
  Misses             550      550           

Flag	Coverage Δ
unittests	70.01% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.