Add manifest_src to CSP, add blob to connect_src (#8967)

config/initializers/content_security_policy.rb

@@ -15,14 +15,15 @@ Rails.application.config.content_security_policy do |p|
   p.style_src       :self, :unsafe_inline, assets_host
   p.media_src       :self, :https, :data, assets_host
   p.frame_src       :self, :https
+  p.manifest_src    :self, assets_host
 
   if Rails.env.development?
     webpacker_urls = %w(ws http).map { |protocol| "#{protocol}#{Webpacker.dev_server.https? ? 's' : ''}://#{Webpacker.dev_server.host_with_port}" }
 
-    p.connect_src :self, assets_host, Rails.configuration.x.streaming_api_base_url, *webpacker_urls
+    p.connect_src :self, :blob, assets_host, Rails.configuration.x.streaming_api_base_url, *webpacker_urls
     p.script_src  :self, :unsafe_inline, :unsafe_eval, assets_host
   else
-    p.connect_src :self, assets_host, Rails.configuration.x.streaming_api_base_url
+    p.connect_src :self, :blob, assets_host, Rails.configuration.x.streaming_api_base_url
     p.script_src  :self, assets_host
   end
 end