Allow to delete any-approval rule using API call

User defined rules are allowed to be deleted

ee/app/models/concerns/approval_rule_like.rb

@@ -50,4 +50,8 @@ module ApprovalRuleLike
   def any_approver?
     raise NotImplementedError
   end
+
+  def user_defined?
+    regular? || any_approver?
+  end
 end

ee/app/policies/approval_merge_request_rule_policy.rb

@@ -4,7 +4,7 @@ class ApprovalMergeRequestRulePolicy < BasePolicy
   delegate { @subject.merge_request }
 
   condition(:editable) do
-    can?(:update_merge_request, @subject.merge_request) && @subject.regular?
+    can?(:update_merge_request, @subject.merge_request) && @subject.user_defined?
   end
 
   rule { editable }.enable :edit_approval_rule

ee/spec/policies/approval_merge_request_rule_policy_spec.rb

@@ -15,7 +15,15 @@ describe ApprovalMergeRequestRulePolicy do
       expect(permissions(merge_request.author, approval_rule)).to be_allowed(:edit_approval_rule)
     end
 
-    context 'when rule is not regular type' do
+    context 'when rule is any-approval' do
+      let(:approval_rule) { build(:any_approver_rule, merge_request: merge_request) }
+
+      it 'allows updating approval rule' do
+        expect(permissions(merge_request.author, approval_rule)).to be_allowed(:edit_approval_rule)
+      end
+    end
+
+    context 'when rule is not user editable' do
       let(:approval_rule) { create(:code_owner_rule, merge_request: merge_request) }
 
       it 'disallows updating approval rule' do