feat: Improve image detection and answer file generation (#1940)

assets/win10x64-iot.xml

@@ -61,6 +61,12 @@
       </DiskConfiguration>
       <ImageInstall>
         <OSImage>
+          <InstallFrom>
+           <MetaData wcm:action="add">
+              <Key>/image/index</Key>
+              <Value>2</Value>
+            </MetaData>
+          </InstallFrom>
           <InstallTo>
             <DiskID>0</DiskID>
             <PartitionID>3</PartitionID>
@@ -81,7 +87,7 @@
         <FullName>Docker</FullName>
         <Organization>Windows for Docker</Organization>
         <ProductKey>
-          <Key>KBN8V-HFGQ4-MGXVD-347P6-PDQGT</Key>
+          <Key />
         </ProductKey>
       </UserData>
       <EnableFirewall>false</EnableFirewall>