plymouth: Fix vconsole setup bug

manifests/profile/base/plymouth.pp

@@ -21,6 +21,15 @@ class nest::profile::base::plymouth {
     ensure => installed,
   }
 
+  # Plymouth tries to start systemd-vconsole-setup before the console is ready,
+  # resulting in I/O error when trying to start the service.
+  file_line { 'plymouth-start.service-Wants':
+    path    => '/lib/systemd/system/plymouth-start.service',
+    line    => 'Wants=systemd-ask-password-plymouth.path',
+    match   => '^Wants=',
+    require => Package['sys-boot/plymouth'],
+  }
+
   $plymouthd_conf_contents = @(PLYMOUTH_CONF)
     [Daemon]
     Theme=details