fix(cloudwatch): NoneType object is not iterable

[HugoPBrito]

Context

cloudwatch_log_group_not_publicly_accessible check is giving this error:

cloudwatch_log_group_not_publicly_accessible -- TypeError[15]: 'NoneType' object is not iterable

Description

A validation has been added to check if the object we are going to iterate over is None or not to avoid it.

Checklist

• Are there new checks included in this PR? No.
• Review if the code is being covered by tests.
• Review if code is being documented following this specification https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings
• Review if backport is needed.
• Review if is needed to change the Readme.md

License

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.36%. Comparing base (ad189b3) to head (ffdb4d3).
Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6671      +/-   ##
==========================================
+ Coverage   89.35%   89.36%   +0.01%     
==========================================
  Files        1182     1182              
  Lines       33815    33816       +1     
==========================================
+ Hits        30214    30220       +6     
+ Misses       3601     3596       -5     

Flag	Coverage Δ
prowler	89.36% <100.00%> (+0.01%)	⬆️

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

Components	Coverage Δ
prowler	89.36% <100.00%> (+0.01%)	⬆️
api	∅ <ø> (∅)

[prowler-bot]

💚 All backports created successfully

Status	Branch	Result
✅	v4.6
✅	v5.0
✅	v5.1
✅	v5.2

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details