SFI: Remove literal machine keys

[Rick-Anderson]

See MachineKey Element (ASP.NET Settings Schema) and also here

Replace

   <machineKey 
        validationKey="32E35872597989D14CC1D5D9F5B1E94238D0EE32CF10AA2D2059533DF6035F4F" 
        decryptionKey="B179091DBB2389B996A526DE8BCD7ACFDBCAB04EF1D085481C61496F693DF5F4" 
    />

with

   <machineKey 
        validationKey="Validation key" 
        decryptionKey="Decryption key" 
    />

@gewarren how do I get this file changed?

[gewarren]

@Rick-Anderson Done in https://docs-archive.visualstudio.com/docs-archive-project/_git/netframework-4-0-docs-archive-pr/pullrequest/10928.