Flaky test BinaryLoggerShouldEmbedFilesViaTaskOutput

In https://dev.azure.com/dnceng-public/public/_build/results?buildId=1419275&view=ms.vss-test-web.build-test-results-tab&runId=39471916&resultId=103677&paneView=debug the test failed with

```
Shouldly.ShouldAssertException : zipArchive.Entries
should contain an element satisfying the condition
zE.Name.EndsWith("testtaskoutputfile.txt")
but does not

Additional Info:
Embedded files:

Stack trace
at Microsoft.Build.UnitTests.BinaryLoggerTests.BinaryLoggerShouldEmbedFilesViaTaskOutput() in /mnt/vss/_work/1/s/src/Build.UnitTests/BinaryLogger_Tests.cs:line 462
at System.RuntimeMethodHandle.InvokeMethod(ObjectHandleOnStack target, Void** arguments, ObjectHandleOnStack sig, BOOL isConstructor, ObjectHandleOnStack result)
at System.RuntimeMethodHandle.InvokeMethod(ObjectHandleOnStack target, Void** arguments, ObjectHandleOnStack sig, BOOL isConstructor, ObjectHandleOnStack result)
at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
```

We should update the test to capture more and more informative logging. We should also fix the cause of the flakiness if it's identifiable. If it's not, let's check in the better logging and get more info on the next flake.