Only verify extensions added by the tests for ETP

[larohra]

Description

Currently, the ETP test in DCR v2 adds bad events for all extensions available on the box. This PR limits those to only those extensions added by the test

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 #2518 (253c138) into develop (3036ae5) will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #2518      +/-   ##
===========================================
+ Coverage    71.91%   71.93%   +0.01%     
===========================================
  Files          101      101              
  Lines        15147    15147              
  Branches      2401     2401              
===========================================
+ Hits         10893    10896       +3     
+ Misses        3773     3770       -3     
  Partials       481      481              

Impacted Files	Coverage Δ
azurelinuxagent/common/event.py	86.03% <0.00%> (+0.67%)	⬆️

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