uploads: autorefresh thumbnails on multi-file uploads page.

Automatically refresh thumbnails on the multi-file upload page as images
are processed in the background.

app/components/media_asset_gallery_component.rb

@@ -3,14 +3,15 @@
 class MediaAssetGalleryComponent < ApplicationComponent
   DEFAULT_SIZE = 180
 
-  attr_reader :inline, :size, :options
+  attr_reader :inline, :size, :classes
 
   renders_many :media_assets
   renders_one :footer
 
-  def initialize(inline: false, size: DEFAULT_SIZE)
+  def initialize(inline: false, size: DEFAULT_SIZE, classes: [])
     super
     @inline = inline
     @size = size
+    @classes = classes
   end
 end