Merge branch 'protected-branch-dropdown-headings' into 'master'

Backport protected branches Ruby change from EE

See merge request !9726

app/assets/stylesheets/framework/dropdowns.scss

@@ -221,6 +221,7 @@
     color: $gl-text-color-secondary;
     font-size: 13px;
     line-height: 22px;
+    text-transform: capitalize;
     padding: 0 10px;
   }
 

app/controllers/projects/protected_branches_controller.rb

@@ -69,10 +69,10 @@ class Projects::ProtectedBranchesController < Projects::ApplicationController
   def access_levels_options
     {
       push_access_levels: {
-        "Roles" => ProtectedBranch::PushAccessLevel.human_access_levels.map { |id, text| { id: id, text: text, before_divider: true } },
+        roles: ProtectedBranch::PushAccessLevel.human_access_levels.map { |id, text| { id: id, text: text, before_divider: true } },
       },
       merge_access_levels: {
-        "Roles" => ProtectedBranch::MergeAccessLevel.human_access_levels.map { |id, text| { id: id, text: text, before_divider: true } }
+        roles: ProtectedBranch::MergeAccessLevel.human_access_levels.map { |id, text| { id: id, text: text, before_divider: true } }
       }
     }
   end