[17.12] Turn off realsig when building product and proto (#17808)

Author: vzarytovskii

eng/Build.ps1

@@ -71,7 +71,7 @@ param (
     [switch]$sourceBuild,
     [switch]$skipBuild,
     [switch]$compressAllMetadata,
-    [switch]$buildnorealsig,
+    [switch]$buildnorealsig = $true,
     [switch]$verifypackageshipstatus = $false,
     [parameter(ValueFromRemainingArguments = $true)][string[]]$properties)
 

eng/build.sh

@@ -71,7 +71,7 @@ skip_analyzers=false
 skip_build=false
 prepare_machine=false
 source_build=false
-buildnorealsig=false
+buildnorealsig=true
 properties=""
 
 docker=false