[naot][android] BasicThreading UnitTest failure

[sbomer]

The TestIsBackgroundProperty check is failing for the thread created with Thread.Start:

11-06 18:10:52.766  3452  3471 I DOTNET  : ===== Running test BasicThreading.Run =====
11-06 18:10:52.986  3452  3471 I DOTNET  : ERROR: Expected CurrentThread.IsBackground == false
11-06 18:10:52.987  3452  3471 I DOTNET  : ERROR: TestIsBackgroundProperty: Expected s_passed == 6, got 5

Like #121216, I see this in ci but can't repro it locally.

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[MichalStrehovsky]

Like #121216, I see this in ci but can't repro it locally.

Android had issues with threading that fail in CI but pass locally: #43754 (comment). The fix for that one involved handling single CPU configuration: #73487. It could possibly related to number of CPUs.