Default enable set_user_availability_status

Default enables the feature flag and
updates related documentation

app/helpers/page_layout_helper.rb

@@ -159,7 +159,7 @@ module PageLayoutHelper
   end
 
   def user_status_properties(user)
-    default_properties = { current_emoji: '', current_message: '', can_set_user_availability: Feature.enabled?(:set_user_availability_status, user), default_emoji: UserStatus::DEFAULT_EMOJI }
+    default_properties = { current_emoji: '', current_message: '', can_set_user_availability: Feature.enabled?(:set_user_availability_status, user, default_enabled: :yaml), default_emoji: UserStatus::DEFAULT_EMOJI }
     return default_properties unless user&.status
 
     default_properties.merge({

app/views/profiles/show.html.haml

@@ -70,7 +70,7 @@
           prepend: emoji_button,
           append: reset_message_button,
           placeholder: s_("Profiles|What's your status?")
-        - if Feature.enabled?(:set_user_availability_status, @user)
+        - if Feature.enabled?(:set_user_availability_status, @user, default_enabled: :yaml)
           .checkbox-icon-inline-wrapper
             = status_form.check_box :availability, { data: { testid: "user-availability-checkbox" }, label: s_("Profiles|Busy"), wrapper_class: 'gl-mr-0 gl-font-weight-bold' }, availability["busy"], availability["not_set"]
             .gl-text-gray-600.gl-ml-5= s_('Profiles|"Busy" will be shown next to your name')

changelogs/unreleased/default-enable-set-user-availability-status.yml

+---
+title: Default enable set_user_availability_status
+merge_request: 51668
+author:
+type: changed

config/feature_flags/development/set_user_availability_status.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/281073
 milestone: '13.6'
 type: development
 group: group::optimize
-default_enabled: false
+default_enabled: true

doc/user/profile/index.md

@@ -203,11 +203,12 @@ If you previously selected the "Busy" checkbox, remember to deselect it when you
 
 ## Busy status indicator
 
-> - Introduced in GitLab 13.6.
-> - It's [deployed behind a feature flag](../feature_flags.md), disabled by default.
-> - It's disabled on GitLab.com.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/259649) in GitLab 13.6.
+> - It was [deployed behind a feature flag](../feature_flags.md), disabled by default.
+> - [Became enabled by default](https://gitlab.com/gitlab-org/gitlab/-/issues/281073) in GitLab 13.8.
+> - It's enabled on GitLab.com.
 > - It's not recommended for production use.
-> - To use it in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-busy-status-feature).
+> - For GitLab self-managed instances, GitLab administrators can opt to [disable it](#disable-busy-status-feature).
 
 To indicate to others that you are busy, you can set an indicator
 
@@ -228,10 +229,16 @@ To set the busy status indicator, either:
   1. Click **Edit profile** (**{pencil}**).
   1. Select the **Busy** checkbox
 
-### Enable busy status feature
+### Disable busy status feature
 
-The busy status feature is deployed behind a feature flag and is **disabled by default**.
-[GitLab administrators with access to the GitLab Rails console](../../administration/feature_flags.md) can enable it for your instance from the [rails console](../../administration/feature_flags.md#start-the-gitlab-rails-console).
+The busy status feature is deployed behind a feature flag and is **enabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../../administration/feature_flags.md) can disable it for your instance from the [rails console](../../administration/feature_flags.md#start-the-gitlab-rails-console).
+
+To disable it:
+
+```ruby
+Feature.disable(:set_user_availability_status)
+```
 
 To enable it: