Fix for 1974140. Delete entry if not valid on hitting home.

If user doesn't enter an APN or name, then delete the entry on hitting home.

And if user has enough information but doesn't enter a name, then set the
name to "Untitled" to avoid blank APNs in the list.

res/values/strings.xml

@@ -2144,4 +2144,7 @@ found in the list of installed applications.</string>
     <string name="backup_erase_dialog_title">Settings backup</string>
     <!-- Dialog title for confirmation to erase backup data from server -->
     <string name="backup_erase_dialog_message">Are you sure you want to stop backing up your settings and erase all copies on Google servers?</string>
+
+    <!-- Name to assign to a Network Access Point that was saved without a name -->
+    <string name="untitled_apn">Untitled</string>
 </resources>