Set dropdown labels for protected branches

[ci skip]

app/views/projects/protected_branches/_access_level_dropdown.html.haml

+- defaultLabel = 'Select'
+- dropdownLabel = defaultLabel
+- access_by_type = protected_branch.merge_access_level_frequencies
+
 - if access_levels.present?
   - access_levels.map.with_index do |level, i|
     - if (level.type == :user)
@@ -9,5 +13,7 @@
     %input{ type: 'hidden', name: "protected_branch[#{input_basic_name}][#{i}][#{fieldKey}]",
                             value: value, data: { type: level.type } }
   
-= dropdown_tag('Select', options: { toggle_class: "#{toggle_class} js-multiselect", dropdown_class: 'dropdown-menu-user dropdown-menu-selectable', filter: true,
-                                    data: { default_label: 'Select' } })
+  - dropdownLabel = [pluralize(access_by_type[:role], 'role'), pluralize(access_by_type[:user], 'user')].to_sentence
+
+= dropdown_tag(dropdownLabel, options: { toggle_class: "#{toggle_class} js-multiselect", dropdown_class: 'dropdown-menu-user dropdown-menu-selectable', filter: true,
+                                    data: { default_label: defaultLabel } })