change COMException default message

Author: OwnageIsMagic

src/libraries/System.Private.CoreLib/src/Resources/Strings.resx

@@ -257,7 +257,7 @@
     <value>Must specify property Set or Get or method call for a COM Object.</value>
   </data>
   <data name="Arg_COMException" xml:space="preserve">
-    <value>Error HRESULT E_FAIL has been returned from a call to a COM component.</value>
+    <value>Unexpected HRESULT has been returned from a call to a COM component.</value>
   </data>
   <data name="Arg_COMPropSetPut" xml:space="preserve">
     <value>Only one of the following binding flags can be set: BindingFlags.SetProperty, BindingFlags.PutDispProperty,  BindingFlags.PutRefDispProperty.</value>

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/ExternalException.cs

@@ -53,7 +53,7 @@ public override string ToString()
 
             string s = $"{GetType()} (0x{HResult:X8})";
 
-            if (!string.IsNullOrEmpty(message ?? SR.Arg_ExternalException))
+            if (!string.IsNullOrEmpty(message))
             {
                 s += ": " + message;
             }