Update T1553.004.yaml (#1386)

Fixed test as it was not working

Co-authored-by: mhaag-spl <76067280+mhaag-spl@users.noreply.github.com>
Co-authored-by: Carrie Roberts <clr2of8@gmail.com>

atomics/T1553.004/T1553.004.yaml

@@ -147,7 +147,7 @@ atomic_tests:
       Get-ChildItem Cert:\LocalMachine\My\$($cert.Thumbprint) | Remove-Item
   executor:
     command: |
-      certutil -addstore my .\test-cert.cer
+      certutil -addstore my #{pfx_path}
     cleanup_command: |
       $cert = Import-Certificate -FilePath #{pfx_path} -CertStoreLocation Cert:\LocalMachine\My
       Get-ChildItem Cert:\LocalMachine\My\$($cert.Thumbprint) -ErrorAction Ignore | Remove-Item -ErrorAction Ignore