feat: Add memory ballooning support (#1688)

assets/win7x86-enterprise.xml

@@ -152,6 +152,15 @@
         </FirewallGroup>
       </FirewallGroups>
     </component>
+    <component name="Microsoft-Windows-Deployment" processorArchitecture="x86" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
+      <RunSynchronous>
+        <RunSynchronousCommand wcm:action="add">
+          <Order>1</Order>
+          <Path>C:\Windows\Drivers\Balloon\blnsvr.exe -i</Path>
+          <Description>Install VirtIO Balloon service</Description>
+        </RunSynchronousCommand>
+      </RunSynchronous>
+    </component>
   </settings>
   <settings pass="oobeSystem">
     <component name="Microsoft-Windows-Shell-Setup" processorArchitecture="x86" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">