Enforce maximum attachment size in project API uploads by default

This makes the feature flag `enforce_max_attachment_size_upload_api`
enabled by default. Previously all uploads via the project API could
bypass the maximum attachment size limit. Now, Workhorse will cut off
the transfer with a "413 Request entity too large" message when that
limit is hit.

This has been enabled on GitLab.com with an exception list since GitLab
13.11.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/325787

Changelog: changed

config/feature_flags/development/enforce_max_attachment_size_upload_api.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/325787
 milestone: '13.11'
 type: development
 group: group::source code
-default_enabled: false
+default_enabled: true

doc/api/projects.md

@@ -2021,7 +2021,8 @@ the format in `markdown` is used.
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/57250) in GitLab 13.11.
 
-GitLab 13.11 added enforcement of the [maximum attachment size limit](../user/admin_area/settings/account_and_limit_settings.md#max-attachment-size) behind the `enforce_max_attachment_size_upload_api` feature flag. GitLab 14.0 will enable this by default.
+GitLab 13.11 added enforcement of the [maximum attachment size limit](../user/admin_area/settings/account_and_limit_settings.md#max-attachment-size) behind the `enforce_max_attachment_size_upload_api` feature flag. GitLab 14.0 enables this by default.
+To disable this enforcement:
 
 **In Omnibus installations:**
 
@@ -2031,10 +2032,10 @@ GitLab 13.11 added enforcement of the [maximum attachment size limit](../user/ad
    sudo gitlab-rails console
    ```
 
-1. Enable the feature flag:
+1. Disable the feature flag:
 
    ```ruby
-   Feature.enable(:enforce_max_attachment_size_upload_api)
+   Feature.disable(:enforce_max_attachment_size_upload_api)
    ```
 
 **In installations from source:**
@@ -2046,10 +2047,10 @@ GitLab 13.11 added enforcement of the [maximum attachment size limit](../user/ad
    sudo -u git -H bundle exec rails console -e production
    ```
 
-1. Enable the feature flag to disable the validation:
+1. Disable the feature flag:
 
    ```ruby
-   Feature.enable(:enforce_max_attachment_size_upload_api)
+   Feature.disable(:enforce_max_attachment_size_upload_api)
    ```
 
 ## Upload a project avatar

lib/api/projects.rb

@@ -61,7 +61,7 @@ module API
       # Temporarily introduced for upload API: https://gitlab.com/gitlab-org/gitlab/-/issues/325788
       def project_attachment_size(user_project)
         return PROJECT_ATTACHMENT_SIZE_EXEMPT if exempt_from_global_attachment_size?(user_project)
-        return user_project.max_attachment_size if Feature.enabled?(:enforce_max_attachment_size_upload_api, user_project)
+        return user_project.max_attachment_size if Feature.enabled?(:enforce_max_attachment_size_upload_api, user_project, default_enabled: :yaml)
 
         PROJECT_ATTACHMENT_SIZE_EXEMPT
       end