Support Mongoid's Storage Field Names

Closes #1745

Author: mshibuya

lib/rails_admin/adapters/mongoid/property.rb

@@ -11,11 +11,11 @@ def initialize(property, model)
         end
 
         def name
-          property.name.to_sym
+          (property.options[:as] || property.name).to_sym
         end
 
         def pretty_name
-          property.name.to_s.tr('_', ' ').capitalize
+          (property.options[:as] || property.name).to_s.tr('_', ' ').capitalize
         end
 
         def type

spec/dummy_app/app/mongoid/field_test.rb

@@ -34,6 +34,7 @@ class FieldTest
   field :open, type: Boolean
   field :restricted_field, type: String
   field :protected_field, type: String
+  field :al, as: :aliased_field, type: String
   has_mongoid_attached_file :paperclip_asset, styles: {thumb: '100x100>'}
 
   field :shrine_asset_data, type: String

spec/rails_admin/adapters/mongoid/property_spec.rb

@@ -195,6 +195,15 @@
     end
   end
 
+  describe 'aliased field' do
+    let(:field) { :aliased_field }
+
+    it 'has correct values' do
+      expect(subject.name).to eq :aliased_field
+      expect(subject.pretty_name).to eq 'Aliased field'
+    end
+  end
+
   describe '#length_validation_lookup' do
     it 'detects validation length properly' do
       class LengthValiated