Provide uid/gid for additional volumes qemu:///session (#1170)

When using qemu:///session, it's necessary to ensure the correct
user/group is passed in when creating additional volume storage as
otherwise the default is to attempt to chown/chgrp it to 0:0 which will
fail.

With this in place and recent changes around uri/qemu_use_session,
remove the checks guarding retrieving the storage pool as it is also
possible for it to be created as expected for the session.

Update create domain tests to check for the correct settings such as
storage path and user/group id's passed to the volume create call for
the additional disks.

Fixes: #986

lib/vagrant-libvirt/action/create_domain.rb

@@ -5,6 +5,7 @@ module VagrantPlugins
     module Action
       class CreateDomain
         include VagrantPlugins::ProviderLibvirt::Util::ErbTemplate
+        include VagrantPlugins::ProviderLibvirt::Util::StorageUtil
 
         def initialize(app, _env)
           @logger = Log4r::Logger.new('vagrant_libvirt::action::create_domain')
@@ -147,12 +148,10 @@ module VagrantPlugins
           # If we have a box, take the path from the domain volume and set our storage_prefix.
           # If not, we dump the storage pool xml to get its defined path.
           # the default storage prefix is typically: /var/lib/libvirt/images/
-          if !config.qemu_use_session
-            if env[:machine].config.vm.box
-              storage_prefix = File.dirname(@domain_volume_path) + '/' # steal
-            else
-              storage_prefix = get_disk_storage_prefix(env, @storage_pool_name)
-            end
+          if env[:machine].config.vm.box
+            storage_prefix = File.dirname(@domain_volume_path) + '/' # steal
+          else
+            storage_prefix = get_disk_storage_prefix(env, @storage_pool_name)
           end
 
           @disks.each do |disk|
@@ -184,6 +183,8 @@ module VagrantPlugins
                 format_type: disk[:type],
                 path: disk[:absolute_path],
                 capacity: disk[:size],
+                owner: storage_uid(env),
+                group: storage_uid(env),
                 #:allocation => ?,
                 pool_name: disk_pool_name
               )