Move Line Item Actions to solidus_legacy_promotions

This table belongs to the legacy promotion system and was,
unfortunately, missed in the original extraction.

(cherry picked from commit d339e84)

core/app/models/spree/line_item.rb

@@ -19,9 +19,6 @@ class LineItem < Spree::Base
     has_many :adjustments, as: :adjustable, inverse_of: :adjustable, dependent: :destroy
     has_many :inventory_units, inverse_of: :line_item
 
-    has_many :line_item_actions, dependent: :destroy
-    has_many :actions, through: :line_item_actions
-
     before_validation :normalize_quantity
     before_validation :set_required_attributes
 

core/db/migrate/20160101010000_solidus_one_four.rb

@@ -197,16 +197,6 @@ def up
       t.index ["variant_id"], name: "index_inventory_units_on_variant_id"
     end
 
-    create_table "spree_line_item_actions", force: :cascade do |t|
-      t.integer "line_item_id", null: false
-      t.integer "action_id", null: false
-      t.integer "quantity", default: 0
-      t.datetime "created_at", precision: 6
-      t.datetime "updated_at", precision: 6
-      t.index ["action_id"], name: "index_spree_line_item_actions_on_action_id"
-      t.index ["line_item_id"], name: "index_spree_line_item_actions_on_line_item_id"
-    end
-
     create_table "spree_line_items", force: :cascade do |t|
       t.integer "variant_id"
       t.integer "order_id"

legacy_promotions/app/decorators/solidus_legacy_promotions/models/spree_line_item_decorator.rb

@@ -2,6 +2,11 @@
 
 module SolidusLegacyPromotions
   module SpreeLineItemDecorator
+    def self.prepended(base)
+      base.has_many :line_item_actions, dependent: :destroy
+      base.has_many :actions, through: :line_item_actions
+    end
+
     def total_before_tax
       amount + adjustments.select { |value| !value.tax? && value.eligible? }.sum(&:amount)
     end

legacy_promotions/db/migrate/20160101010001_solidus_one_four_promotions.rb

@@ -122,5 +122,17 @@ def up
         t.index ["starts_at"], name: "index_spree_promotions_on_starts_at"
       end
     end
+
+    unless table_exists?(:spree_line_item_actions)
+      create_table "spree_line_item_actions", force: :cascade do |t|
+        t.integer "line_item_id", null: false
+        t.integer "action_id", null: false
+        t.integer "quantity", default: 0
+        t.datetime "created_at", precision: 6
+        t.datetime "updated_at", precision: 6
+        t.index ["action_id"], name: "index_spree_line_item_actions_on_action_id"
+        t.index ["line_item_id"], name: "index_spree_line_item_actions_on_line_item_id"
+      end
+    end
   end
 end