Set for for labels and ID for dropdowns on create form

app/assets/javascripts/protected_branch_access_dropdown.js.es6

@@ -8,6 +8,7 @@
       $dropdown.glDropdown({
         data: data,
         selectable: true,
+        inputId: $dropdown.data('input-id'),
         fieldName: $dropdown.data('field-name'),
         toggleLabel(item) {
           return item.text;

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

@@ -6,7 +6,7 @@
     .panel-body
       .form-horizontal
         .form-group
-          %label.col-md-2.text-right
+          = f.label :name, class: 'col-md-2 text-right' do
             Branch:
           .col-md-10
             = render partial: "dropdown", locals: { f: f }
@@ -18,19 +18,19 @@
               %code production/*
               are supported
         .form-group
-          %label.col-md-2.text-right
+          %label.col-md-2.text-right{ for: 'merge_access_level_attributes' }
             Allowed to merge:
           .col-md-10
             = dropdown_tag('Select',
                            options: { toggle_class: 'js-allowed-to-merge wide',
-                           data: { field_name: 'protected_branch[merge_access_level_attributes][access_level]' }})
+                           data: { field_name: 'protected_branch[merge_access_level_attributes][access_level]', input_id: 'merge_access_level_attributes' }})
         .form-group
-          %label.col-md-2.text-right
+          %label.col-md-2.text-right{ for: 'push_access_level_attributes' }
             Allowed to push:
           .col-md-10
             = dropdown_tag('Select',
                            options: { toggle_class: 'js-allowed-to-push wide',
-                           data: { field_name: 'protected_branch[push_access_level_attributes][access_level]' }})
+                           data: { field_name: 'protected_branch[push_access_level_attributes][access_level]', input_id: 'push_access_level_attributes' }})
 
     .panel-footer
       = f.submit 'Protect', class: 'btn-create btn', disabled: true