Undo explicit conversion to Integer

With the changes in Gitlab::VisibilityLevel it is no longer needed to
explicit conversion to Integer in the controller itself.

app/controllers/admin/application_settings_controller.rb

@@ -45,18 +45,6 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
   end
 
   def application_setting_params
-    default_visibilities = [:default_project_visibility, :default_snippet_visibility, :default_group_visibility]
-
-    default_visibilities.each do |visibility|
-      value = params[:application_setting][visibility]
-      params[:application_setting][visibility] =
-        if value.present?
-          value.to_i
-        else
-          Gitlab::VisibilityLevel::PRIVATE
-        end
-    end
-
     restricted_levels = params[:application_setting][:restricted_visibility_levels]
     if restricted_levels.nil?
       params[:application_setting][:restricted_visibility_levels] = []

spec/controllers/admin/application_settings_controller_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe Admin::ApplicationSettingsController do
+  include StubENV
+
+  let(:admin) { create(:admin) }
+
+  before do
+    sign_in(admin)
+    stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
+  end
+
+  describe 'PATCH #update' do
+    it 'updates the default_project_visibility for string value' do
+      patch :update, application_setting: { default_project_visibility: "20" }
+
+      expect(response).to redirect_to(admin_application_settings_path)
+      expect(ApplicationSetting.current.default_project_visibility).to eq Gitlab::VisibilityLevel::PUBLIC
+    end
+
+    it 'falls back to default with default_project_visibility setting is omitted' do
+      patch :update, application_setting: {}
+
+      expect(response).to redirect_to(admin_application_settings_path)
+      expect(ApplicationSetting.current.default_project_visibility).to eq Gitlab::VisibilityLevel::PRIVATE
+    end
+  end
+end