Issue #3271144: Ensure new, changed or deleted service definitions are in the correct state after an update

package_manager/tests/fixtures/updated_module/1.0.0/updated_module.services.yml

+services:
+  updated_module.existing_service:
+    class: stdClass
+    properties:
+      value: 'Pre-update value'
+  updated_module.deleted_service:
+    class: stdClass
+    properties:
+      value: 'Deleted service, should not exist after update'