fix: set default values for aadToken & url for internal Synapse

[serena-ruan]

Related Issues/PRs

#xxx

What changes are proposed in this pull request?

Briefly describe the changes included in this Pull Request.

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6. Make sure the WebsiteSamplesTests job pass in the pipeline.

[github-actions]

Hey @serena-ruan 👋!
Thank you so much for contributing to our repository 🙌.
Someone from SynapseML Team will be reviewing this pull request soon.

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• fix: Fix LightGBM crashes with empty partitions
• feat: Make HTTP on Spark back-offs configurable
• docs: Update Spark Serving usage
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• style: Remove nulls from CNTKModel
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[serena-ruan]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov-commenter]

Codecov Report

Merging #1918 (75f16dc) into master (4912ae4) will increase coverage by 0.00%.
The diff coverage is 40.00%.

@@           Coverage Diff           @@
##           master    #1918   +/-   ##
=======================================
  Coverage   85.85%   85.85%           
=======================================
  Files         301      301           
  Lines       15621    15622    +1     
  Branches      821      813    -8     
=======================================
+ Hits        13412    13413    +1     
  Misses       2209     2209           

Impacted Files	Coverage Δ
...re/synapse/ml/cognitive/CognitiveServiceBase.scala	81.18% <40.00%> (-0.98%)	⬇️

... and 2 files with indirect coverage changes

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