Restore import_export.yml per CE

For reasons unknown, the EE version of this file contained various
duplicate entries. This commit restores this file based on the CE
version, ensuring that both CE and EE use the same YAML data.

lib/gitlab/import_export/import_export.yml

@@ -71,9 +71,6 @@ project_tree:
   - protected_branches:
     - :merge_access_levels
     - :push_access_levels
-    - :unprotect_access_levels
-  - protected_environments:
-    - :deploy_access_levels
   - protected_tags:
     - :create_access_levels
   - :project_feature
@@ -87,9 +84,6 @@ project_tree:
     - lists:
       - label:
         - :priorities
-      - milestone:
-        - events:
-          - :push_event_payload
 
 # Only include the following attributes for the models specified.
 included_attributes:
@@ -128,18 +122,10 @@ excluded_attributes:
     - :last_activity_at
     - :last_repository_updated_at
     - :last_repository_check_at
-    - :mirror_user_id
-    - :mirror_trigger_builds
     - :storage_version
     - :remote_mirror_available_overridden
-    - :only_mirror_protected_branches
-    - :pull_mirror_available_overridden
-    - :mirror_overwrites_diverged_branches
     - :description_html
     - :repository_languages
-    - :packages_enabled
-    - :mirror_last_update_at
-    - :mirror_last_successful_update_at
     - :bfg_object_map
     - :detected_repository_languages
     - :tag_list