Add custom emojis to the emoji picker (#5052)

app/serializers/initial_state_serializer.rb

@@ -4,6 +4,12 @@ class InitialStateSerializer < ActiveModel::Serializer
   attributes :meta, :compose, :accounts,
              :media_attachments, :settings, :push_subscription
 
+  has_many :custom_emojis, serializer: REST::CustomEmojiSerializer
+
+  def custom_emojis
+    CustomEmoji.local
+  end
+
   def meta
     store = {
       streaming_api_base_url: Rails.configuration.x.streaming_api_base_url,