Fix failing tests relating to backporting ee!581.

1. `GitPushService` was still using `{merge,push}_access_level_attributes` instead
   of `{merge,push}_access_levels_attributes`.

2. The branches API creates access levels regardless of the state of the
   `developers_can_{push,merge}` parameters. This is in line with the UI,
   where Master access is the default for a new protected branch.

3. Use `after(:build)` to create access levels in the
   `protected_branches` factory, so that `factories_spec` passes. It
   only builds records, so we need to create access levels on `build` as
   well.

1 files changed, 4 insertions, 4 deletions

diff --git a/app/services/git_push_service.rb b/app/services/git_push_service.rb
index 6f521462cf3..d5fb2018d24 100644
--- a/app/services/git_push_service.rb
+++ b/app/services/git_push_service.rb
@@ -91,12 +91,12 @@ class GitPushService < BaseService
 
       params = {
         name: @project.default_branch,
-        push_access_level_attributes: {
+        push_access_levels_attributes: [{
           access_level: current_application_settings.default_branch_protection == PROTECTION_DEV_CAN_PUSH ? Gitlab::Access::DEVELOPER : Gitlab::Access::MASTER
-        },
-        merge_access_level_attributes: {
+        }],
+        merge_access_levels_attributes: [{
           access_level: current_application_settings.default_branch_protection == PROTECTION_DEV_CAN_MERGE ? Gitlab::Access::DEVELOPER : Gitlab::Access::MASTER
-        }
+        }]
       }
 
       ProtectedBranches::CreateService.new(@project, current_user, params).execute