Unit tests for the SensitiveDataLogger

[alexmg]

Motivation and Context (Why the change? What's the scenario?)

Contributing unit tests for the SensitiveDataLogger to cover a recently fixed bug and prevent future regression.

High level description (Approach, Design)

N/A - unit tests only

[alexmg]

These unit tests provide coverage for the problem raised in #851

[alexmg]

@microsoft-github-policy-service agree

[dluc]

Minor changes for readability and to handle string case. Fixed Dispose.

One thing I would improve is making sure tests do not run in parallel, because they act on shared state, e.g. the static .Enabled and the env var. I tried adding an

Assert.False(SensitiveDataLogger.Enabled);

at the start of each test.