Update spec to cover casting of value to bool

spec/serializers/service_field_entity_spec.rb

@@ -55,12 +55,12 @@ RSpec.describe ServiceFieldEntity do
     end
 
     context 'EmailsOnPush Service' do
-      let(:service) { create(:emails_on_push_service) }
+      let(:service) { create(:emails_on_push_service, send_from_committer_email: '1') }
 
       context 'field with type checkbox' do
         let(:field) { service.global_fields.find { |field| field[:name] == 'send_from_committer_email' } }
 
-        it 'exposes correct attributes' do
+        it 'exposes correct attributes and casts value to Boolean' do
           expected_hash = {
             type: 'checkbox',
             name: 'send_from_committer_email',