"Allocated native memory" and "Native memory leak" show wrong values if I use KeepBenchmarkFiles

[yaskovdev]

Steps to reproduce:

1. Clone the solution.
2. Open PowerShell in the same directory as BenchmarkDotNetBug.sln as an admin.
3. Run .\BuildAndRun.ps1.
4. Wait a few minutes for the benchmark to finish.

Expected: both "Allocated native memory" and "Native memory leak" are "10 B".
Actual: both "Allocated native memory" and "Native memory leak" are "-".

Remove KeepBenchmarkFiles attribute from MemoryLeak class and run again. This time everything works as expected.

// Benchmark Process Environment Information:
// Runtime=.NET 6.0.8 (6.0.822.36306), X64 RyuJIT AVX2
// GC=Concurrent Workstation
// HardwareIntrinsics=AVX2,AES,BMI1,BMI2,FMA,LZCNT,PCLMUL,POPCNT VectorSize=256
// Job: DefaultJob