Updated Milestone Badges to GlBadge

app/views/shared/_milestone_expired.html.haml

 - if milestone.expired? && !milestone.closed?
-  .gl-badge.badge-warning.badge-pill.gl-mb-2= _('Expired')
+  = gl_badge_tag _('Expired'), { variant: :warning }, { class: "gl-mb-2" }
 - if milestone.upcoming?
-  .gl-badge.badge-primary.badge-pill.gl-mb-2= _('Upcoming')
+  = gl_badge_tag _('Upcoming'), { variant: :info }, { class: "gl-mb-2" }
 - if milestone.closed?
-  .gl-badge.badge-danger.badge-pill.gl-mb-2= _('Closed')
+  = gl_badge_tag _('Closed'), { variant: :danger }, { class: "gl-mb-2" }

app/views/shared/milestones/_milestone.html.haml

@@ -33,11 +33,9 @@
       %div
         = render('shared/milestone_expired', milestone: milestone)
         - if milestone.group_milestone?
-          .gl-badge.badge-info.badge-pill
-            = milestone.group.full_name
+          = gl_badge_tag milestone.group.full_name, variant: :info
         - if milestone.project_milestone?
-          .gl-badge.badge-muted.badge-pill
-            = milestone.project.full_name
+          = gl_badge_tag milestone.project.full_name, variant: :muted
 
     .col-sm-4.milestone-progress
       = milestone_progress_bar(milestone)