fix: The product name should come from SMBIOS 'Product Name'

Unless you are LENOVO or IBM in which case they have forever put their
product names in the 'Version' field instead.

This fixes the default hostname being nonsensical on non-Lenovo systems.

Closes: https://bugs.launchpad.net/bugs/2056167
Closes: canonical/ubuntu-desktop-installer#2394

packages/ubuntu_provision/lib/src/identity/identity_model.dart

@@ -202,6 +202,8 @@ class IdentityModel extends SafeChangeNotifier with PropertyStreamNotifier {
 const kDMIProductNameFile = '/sys/devices/virtual/dmi/id/product_name';
 @visibleForTesting
 const kDMIProductVersionFile = '/sys/devices/virtual/dmi/id/product_version';
+@visibleForTesting
+const kDMIVendorFile = '/sys/devices/virtual/dmi/id/sys_vendor';
 
 Future<String> _readDmiFile(String path) {
   return File(path)
@@ -211,11 +213,18 @@ Future<String> _readDmiFile(String path) {
 }
 
 Future<String> _readProductName() async {
-  /// Lenovo uses product_version as product name
-  /// and it's empty on HP and DELL
-  var productName = await _readDmiFile(kDMIProductVersionFile);
-  if (productName.isEmpty) {
+  String productName;
+  final vendor = await _readDmiFile(kDMIVendorFile);
+  if (vendor == 'IBM' || vendor == 'LENOVO') {
+    productName = await _readDmiFile(kDMIProductVersionFile);
+    if (productName.isEmpty) {
+      productName = await _readDmiFile(kDMIProductNameFile);
+    }
+  } else {
     productName = await _readDmiFile(kDMIProductNameFile);
+    if (productName.isEmpty) {
+      productName = await _readDmiFile(kDMIProductVersionFile);
+    }
   }
   return productName;
 }