Enable merge_request_reviewers FF

Issue: https://gitlab.com/gitlab-org/gitlab/-/issues/245190

app/models/merge_request.rb

@@ -1695,7 +1695,7 @@ class MergeRequest < ApplicationRecord
   end
 
   def allows_reviewers?
-    Feature.enabled?(:merge_request_reviewers, project)
+    Feature.enabled?(:merge_request_reviewers, project, default_enabled: true)
   end
 
   def allows_multiple_reviewers?

app/views/projects/merge_requests/_merge_request.html.haml

@@ -55,7 +55,7 @@
         - if merge_request.assignees.any?
           %li.gl-display-flex.gl-align-items-center
             = render 'shared/issuable/assignees', project: merge_request.project, issuable: merge_request
-        - if Feature.enabled?(:merge_request_reviewers, @project) && merge_request.reviewers.any?
+        - if Feature.enabled?(:merge_request_reviewers, @project, default_enabled: true) && merge_request.reviewers.any?
           %li.gl-display-flex.issuable-reviewers
             = render 'shared/issuable/reviewers', project: merge_request.project, issuable: merge_request
         = render 'projects/merge_requests/approvals_count', merge_request: merge_request

app/views/shared/issuable/_sidebar.html.haml

@@ -25,7 +25,7 @@
       .block.assignee.qa-assignee-block
         = render "shared/issuable/sidebar_assignees", issuable_sidebar: issuable_sidebar, assignees: assignees, signed_in: signed_in
 
-      - if Feature.enabled?(:merge_request_reviewers, @project) && reviewers
+      - if Feature.enabled?(:merge_request_reviewers, @project, default_enabled: true) && reviewers
         .block.reviewer.qa-reviewer-block
           = render "shared/issuable/sidebar_reviewers", issuable_sidebar: issuable_sidebar, reviewers: reviewers, signed_in: signed_in
 

config/feature_flags/development/merge_request_reviewers.yml

@@ -4,4 +4,4 @@ introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40488
 rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/245190
 group: group::source code
 type: development
-default_enabled: false
+default_enabled: true