Adding more sources to security sources list

[rane-rajasi]

Changes include:

• adding /etc/apt/sources.list.d/ as well to the security sources list
• Removed error raised on this command failure (NOTE: This comes from the ask of not blocking the operation on this error but issuing a warning to the customer)

This should take care of the change attempted in: #176

[codecov]

Codecov Report

Merging #208 (e0549e5) into master (f3b7c7b) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #208      +/-   ##
==========================================
- Coverage   90.12%   90.11%   -0.01%     
==========================================
  Files          90       90              
  Lines       14445    14442       -3     
==========================================
- Hits        13018    13015       -3     
  Misses       1427     1427              

Flag	Coverage Δ
python27	90.11% <100.00%> (-0.01%)	⬇️
python39	90.11% <100.00%> (-0.01%)	⬇️

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Impacted Files	Coverage Δ
...ore/src/package_managers/AptitudePackageManager.py	89.60% <100.00%> (-0.07%)	⬇️
src/core/tests/library/LegacyEnvLayerExtensions.py	94.71% <100.00%> (ø)