providers/virtualbox: name for private network chooses right interface

[GH-5389]

CHANGELOG.md

@@ -102,6 +102,8 @@ BUG FIXES:
       on Windows [GH-1483]
   - providers/virtualbox: Error if another user is running after a VM is
       created to avoid issue with VirtualBox "losing" the VM [GH-5895]
+  - providers/virtualbox: The "name" setting on private networks will
+      choose an existing hostonly network [GH-5389]
   - provisioners/ansible: fix SSH settings to support more than 5 ssh keys [GH-5017]
   - provisioners/ansible: increase ansible connection timeout to 30 seconds [GH-5018]
   - provisioners/ansible: disable color if Vagrant is not colored [GH-5531, GH-5532]

plugins/providers/virtualbox/action/network.rb

@@ -306,6 +306,7 @@ module VagrantPlugins
             auto_config: options[:auto_config],
             ip:          options[:ip],
             mac:         options[:mac],
+            name:        options[:name],
             netmask:     options[:netmask],
             nic_type:    options[:nic_type],
             type:        options[:type]