Extract EE specific files/lines for app/services/groups

We have the following files containing EE specific code. We should move them to ee/

app/services/groups/create_service.rb

diff --git a/app/services/groups/create_service.rb b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/app/services/groups/create_service.rb
index 55a3b9fa7b1..cdc205fafcf 100644
--- a/app/services/groups/create_service.rb
+++ b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/app/services/groups/create_service.rb
@@ -33,7 +33,7 @@ module Groups
     private
 
     def after_build_hook(group, params)
-      # overriden in EE
+      # overridden in EE
     end
 
     def create_chat_team?
@@ -69,3 +69,5 @@ module Groups
     end
   end
 end
+
+Groups::CreateService.prepend(EE::Groups::CreateService)

app/services/groups/update_service.rb

diff --git a/app/services/groups/update_service.rb b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/app/services/groups/update_service.rb
index 9ff1da270e2..2e849887296 100644
--- a/app/services/groups/update_service.rb
+++ b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/app/services/groups/update_service.rb
@@ -31,7 +31,7 @@ module Groups
     private
 
     def before_assignment_hook(group, params)
-      # overriden in EE
+      # overridden in EE
     end
 
     def after_update
@@ -60,3 +60,5 @@ module Groups
     end
   end
 end
+
+Groups::UpdateService.prepend(EE::Groups::UpdateService)