Monitor extension memory cgroups

[nagworld9]

Description

Update the extension unit file having memoryaccounting enabled and create drop-in file for services.
Add the memory controllers to the monitor thread to start tracking those. Stop tracking those controllers once ext uninstall.

Issue #

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PR information

• The title of the PR is clear and informative.
• There are a small number of commits, each of which has an informative message. This means that previously merged commits do not appear in the history of the PR. For information on cleaning up the commits in your pull request, see this page.
• If applicable, the PR references the bug/issue that it fixes in the description.
• New Unit tests were added for the changes made

Quality of Code and Contribution Guidelines

• I have read the contribution guidelines.

[codecov]

Codecov Report

Merging #2632 (3f40e11) into develop (45018d7) will decrease coverage by 0.00%.
The diff coverage is 73.17%.

❗ Current head 3f40e11 differs from pull request most recent head c9202de. Consider uploading reports for the commit c9202de to get more accurate results

@@             Coverage Diff             @@
##           develop    #2632      +/-   ##
===========================================
- Coverage    71.97%   71.96%   -0.01%     
===========================================
  Files          103      103              
  Lines        15609    15632      +23     
  Branches      2483     2488       +5     
===========================================
+ Hits         11234    11250      +16     
- Misses        3864     3868       +4     
- Partials       511      514       +3     

Impacted Files	Coverage Δ
azurelinuxagent/common/cgroupapi.py	81.00% <71.42%> (-0.61%)	⬇️
azurelinuxagent/common/cgroupconfigurator.py	73.47% <72.41%> (-0.21%)	⬇️
azurelinuxagent/ga/exthandlers.py	85.87% <75.00%> (ø)
azurelinuxagent/common/cgroup.py	87.86% <100.00%> (ø)
azurelinuxagent/common/utils/fileutil.py	79.69% <0.00%> (+0.75%)	⬆️

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[narrieta]

@nagworld9 can we improve the description (short summary of what the issue and fix are). Thanks

[narrieta]

LGT, please update the description

[nagworld9]

LGT, please update the description

Updated, thanks for the approval.