Enable dependency_list_vulnerabilities by default

This enables the `dependency_list_vulnerabilities` feature flag by
default, as part of the feature[1] to add dependency scanning results to
the Dependency List.

[1]: https://gitlab.com/gitlab-org/gitlab-ee/issues/10077

Add changelog entry

ee/app/controllers/projects/dependencies_controller.rb

@@ -5,7 +5,7 @@ module Projects
     before_action :check_feature_enabled!
 
     before_action do
-      push_frontend_feature_flag(:dependency_list_vulnerabilities)
+      push_frontend_feature_flag(:dependency_list_vulnerabilities, default_enabled: true)
     end
 
     def check_feature_enabled!

ee/changelogs/unreleased/10077-enable-dependency-list-vulnerabilities-feature-flag-ee.yml

+---
+title: Add Dependency Scanning information to the Dependency List.
+merge_request: 14955
+author:
+type: added