Add injectionMode option for APM instrumentation

[iamluc]

What does this PR do?

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Motivation

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Additional Notes

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Minimum Agent Versions

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• Agent: vX.Y.Z
• Cluster Agent: vX.Y.Z

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Checklist

• PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• PR has a milestone or the qa/skip-qa label
• All commits are signed (see: signing commits)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 16.66667% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 38.37%. Comparing base (43bd941) to head (4b74189).

Files with missing lines	Patch %	Lines
...nal/controller/datadogagent/feature/apm/feature.go	16.66%	4 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2504      +/-   ##
==========================================
- Coverage   38.38%   38.37%   -0.01%     
==========================================
  Files         300      300              
  Lines       25555    25561       +6     
==========================================
+ Hits         9809     9810       +1     
- Misses      15002    15006       +4     
- Partials      744      745       +1     

Flag	Coverage Δ
unittests	38.37% <16.66%> (-0.01%)	⬇️

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Files with missing lines	Coverage Δ
...nal/controller/datadogagent/feature/apm/feature.go	67.79% <16.66%> (-1.07%)	⬇️

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[iamluc]

Superseded by #2655