Remove null check that is not needed.

Author: vcsjones

src/libraries/Common/src/Interop/Android/System.Security.Cryptography.Native.Android/Interop.X509Chain.cs

@@ -22,9 +22,9 @@ internal static SafeX509ChainContextHandle X509ChainCreateContext(SafeX509Handle
         {
             SafeX509ChainContextHandle chainContext = X509ChainCreateContext(cert, extraStore, extraStore.Length);
 
-            if (chainContext is null || chainContext.IsInvalid)
+            if (chainContext.IsInvalid)
             {
-                chainContext?.Dispose();
+                chainContext.Dispose();
                 throw new CryptographicException(SR.Cryptography_AndroidX509ChainContextInitializationFailed);
             }