[NativeAOT] Investigate failing DoNotLeakWeakReferences

[simonrozsival]

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1468779

Failure:

DoNotLeakWeakReferences
System.Exception : Worker thread failed
----> NUnit.Framework.AssertionException :   #2
Expected: 25 +/- 10
But was:  51
Off by:   -26.0d

   at Java.InteropTests.JnienvTest.DoNotLeakWeakReferences()
   at System.Reflection.DynamicInvokeInfo.Invoke(Object, IntPtr, Object[], BinderBundle, Boolean)
--AssertionException
   at NUnit.Framework.Assert.ReportFailure(String)
   at NUnit.Framework.Assert.ReportFailure(ConstraintResult, String, Object[])
   at NUnit.Framework.Assert.That[TActual](TActual, IResolveConstraint, String, Object[])
   at Java.InteropTests.JnienvTest.<>c__DisplayClass32_0.<DoNotLeakWeakReferences>b__1()