add api support

ee/lib/api/project_approvals.rb

@@ -30,7 +30,8 @@ module API
           optional :disable_overriding_approvers_per_merge_request, type: Boolean, desc: 'Should MRs be able to override approvers and approval count'
           optional :merge_requests_author_approval, type: Boolean, desc: 'Should merge request authors be able to self approve merge requests; `true` means authors cannot self approve'
           optional :merge_requests_disable_committers_approval, type: Boolean, desc: 'Should committers be able to self approve merge requests'
-          at_least_one_of :approvals_before_merge, :reset_approvals_on_push, :disable_overriding_approvers_per_merge_request, :merge_requests_author_approval, :merge_requests_disable_committers_approval
+          optional :require_password_to_approve, type: Boolean, desc: 'Should approvers authenticate via password before adding approval'
+          at_least_one_of :approvals_before_merge, :reset_approvals_on_push, :disable_overriding_approvers_per_merge_request, :merge_requests_author_approval, :merge_requests_disable_committers_approval, :require_password_to_approve
         end
         post '/' do
           project_params = declared(params, include_missing: false, include_parent_namespaces: false)

ee/lib/ee/api/entities.rb

@@ -506,6 +506,7 @@ module EE
         expose :disable_overriding_approvers_per_merge_request
         expose :merge_requests_author_approval
         expose :merge_requests_disable_committers_approval
+        expose :require_password_to_approve
       end
 
       class Approvals < Grape::Entity

ee/spec/fixtures/api/schemas/public_api/v4/project_approvers.json

@@ -6,6 +6,7 @@
     "reset_approvals_on_push": { "type": "boolean" },
     "merge_requests_author_approval": { "type": ["boolean", "null"] },
     "merge_requests_disable_committers_approval": { "type": ["boolean", "null"] },
+    "require_password_to_approve": { "type": ["boolean", "null"] },
     "approvers": {
       "type": "array",
       "items": {

ee/spec/requests/api/project_approvals_spec.rb

@@ -69,6 +69,7 @@ describe API::ProjectApprovals do
           project.disable_overriding_approvers_per_merge_request = true
           project.merge_requests_author_approval = false
           project.merge_requests_disable_committers_approval = true
+          project.require_password_to_approve = true
           project.save
 
           settings = {
@@ -76,7 +77,8 @@ describe API::ProjectApprovals do
             reset_approvals_on_push: true,
             disable_overriding_approvers_per_merge_request: false,
             merge_requests_author_approval: true,
-            merge_requests_disable_committers_approval: false
+            merge_requests_disable_committers_approval: false,
+            require_password_to_approve: true
           }
 
           post api(url, current_user), params: settings