Fix Rails/SaveBang offenses

Changelog: other
EE: true

.rubocop_todo/rails/save_bang.yml

 ---
 Rails/SaveBang:
   Exclude:
-  - ee/spec/initializers/fog_google_https_private_urls_spec.rb
   - ee/spec/lib/analytics/merge_request_metrics_calculator_spec.rb
   - ee/spec/lib/ee/gitlab/auth/ldap/sync/group_spec.rb
   - ee/spec/lib/ee/gitlab/checks/push_rules/commit_check_spec.rb

ee/spec/initializers/fog_google_https_private_urls_spec.rb

@@ -13,8 +13,8 @@ RSpec.describe 'Fog::Storage::GoogleXML::File' do
   end
 
   let(:file) do
-    directory = storage.directories.create(key: 'data')
-    directory.files.create(
+    directory = storage.directories.create(key: 'data') # rubocop:disable Rails/SaveBang
+    directory.files.create(                             # rubocop:disable Rails/SaveBang
       body: 'Hello World!',
       key: 'hello_world.txt'
     )