Fix new branch dropdown position and size

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/32096

app/views/projects/branches/new.html.haml

@@ -17,11 +17,13 @@
       .help-block.text-danger.js-branch-name-error
   .form-group
     = label_tag :ref, 'Create from', class: 'control-label'
-    .col-sm-10.dropdown.create-from
-      = hidden_field_tag :ref, default_ref
-      = button_tag type: 'button', title: default_ref, class: 'dropdown-toggle form-control js-branch-select', required: true, data: { toggle: 'dropdown', selected: default_ref, field_name: 'ref' } do
-        .text-left.dropdown-toggle-text= default_ref
-      = render 'shared/ref_dropdown', dropdown_class: 'wide'
+    .col-sm-10.create-from
+      .dropdown
+        = hidden_field_tag :ref, default_ref
+        = button_tag type: 'button', title: default_ref, class: 'dropdown-menu-toggle wide form-control js-branch-select', required: true, data: { toggle: 'dropdown', selected: default_ref, field_name: 'ref' } do
+          .text-left.dropdown-toggle-text= default_ref
+          = icon('chevron-down')
+        = render 'shared/ref_dropdown', dropdown_class: 'wide'
       .help-block Existing branch name, tag, or commit SHA
   .form-actions
     = button_tag 'Create branch', class: 'btn btn-create', tabindex: 3