Fix typo in parameter name and set default value to true.

[mgreisen]

Summary of the Pull Request

Closes #3071

Fix the typo in the azcopy parameter name and set the default value to true.

PR Checklist

• Applies to work item: #xxx
• CLA signed. If not, go over here and sign the CLI.
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Info on Pull Request

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Validation Steps Performed

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[codecov-commenter]

Codecov Report

Merging #3085 (796deeb) into main (bb1a544) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##             main    #3085   +/-   ##
=======================================
  Coverage   31.75%   31.75%           
=======================================
  Files         307      307           
  Lines       36770    36770           
=======================================
  Hits        11678    11678           
  Misses      25092    25092           

Impacted Files	Coverage Δ
src/agent/onefuzz/src/az_copy.rs	0.00% <0.00%> (ø)