[ASP.NET Core] Fix few tests

[vishweshbankwar]

Fixes #.

Changes

Please provide a brief description of the changes here.

For significant contributions please make sure you have completed the following items:

• Appropriate CHANGELOG.md updated for non-trivial changes
• Design discussion issue #
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #3906 (a7381aa) into main (f770047) will increase coverage by 0.01%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3906      +/-   ##
==========================================
+ Coverage   87.31%   87.32%   +0.01%     
==========================================
  Files         279      279              
  Lines       10781    10781              
==========================================
+ Hits         9413     9415       +2     
+ Misses       1368     1366       -2     

Impacted Files	Coverage Δ
...ZPages/Implementation/ZPagesExporterEventSource.cs	56.25% <0.00%> (-6.25%)	⬇️
...p/Implementation/HttpInstrumentationEventSource.cs	72.00% <0.00%> (-4.00%)	⬇️
...emetry.Api/Internal/OpenTelemetryApiEventSource.cs	79.41% <0.00%> (-2.95%)	⬇️
...tation/OpenTelemetryProtocolExporterEventSource.cs	95.00% <0.00%> (+10.00%)	⬆️
...porter.OpenTelemetryProtocol/OtlpMetricExporter.cs	86.36% <0.00%> (+13.63%)	⬆️

[cijothomas]

Failed OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests.MockCollectorIntegrationTests.TestRecoveryAfterFailedExport [1 s]
Error Message:
Assert.Equal() Failure
Expected: Failure
Actual: Success
Stack Trace:
at OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests.MockCollectorIntegrationTests.TestRecoveryAfterFailedExport() in D:\a\opentelemetry-dotnet\opentelemetry-dotnet\test\OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests\MockCollectorIntegrationTests.cs:line 101
--- End of stack trace from previous location ---