Verify handle when adding certificate

Make sure we verify that a certificate's handle is valid before adding it to the store.

Fix #12223

src/System.Security.Cryptography.X509Certificates/src/System/Security/Cryptography/X509Certificates/X509Store.cs

@@ -128,6 +128,9 @@ public void Add(X509Certificate2 certificate)
         {
             if (certificate == null)
                 throw new ArgumentNullException(nameof(certificate));
+
+            if (certificate.Handle == IntPtr.Zero)
+                throw new ArgumentNullException(nameof(certificate));
 
             if (_storePal == null)
                 throw new CryptographicException(SR.Cryptography_X509_StoreNotOpen);