Add update_issuable_metric_image ability

Use this for metric image update

ee/app/policies/ee/issuable_policy.rb

@@ -31,11 +31,13 @@ module EE
       end
 
       rule { is_author | can?(:create_issue) & can?(:update_issue) }.policy do
+        enable :update_issuable_metric_image
         enable :destroy_issuable_metric_image
       end
 
       rule { ~is_project_member }.policy do
         prevent :upload_issuable_metric_image
+        prevent :update_issuable_metric_image
         prevent :destroy_issuable_metric_image
       end
     end

ee/lib/ee/api/issues.rb

@@ -83,7 +83,7 @@ module EE
             put ':metric_image_id' do
               issue = find_project_issue(params[:issue_iid])
 
-              authorize!(:destroy_issuable_metric_image, issue)
+              authorize!(:update_issuable_metric_image, issue)
 
               metric_image = issue.metric_images.find_by_id(params[:metric_image_id])
 

ee/spec/policies/issuable_policy_spec.rb

@@ -30,19 +30,19 @@ RSpec.describe IssuablePolicy, models: true do
 
       it 'disallows non-members from creating and deleting metric images' do
         expect(permissions(non_member, issue)).to be_allowed(:read_issuable_metric_image)
-        expect(permissions(non_member, issue)).to be_disallowed(:upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(non_member, issue)).to be_disallowed(:upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
       end
 
       it 'allows guests to read, create metric images, and delete them in their own issues' do
         expect(permissions(guest, issue)).to be_allowed(:read_issuable_metric_image)
         expect(permissions(guest, issue)).to be_disallowed(:upload_issuable_metric_image, :destroy_issuable_metric_image)
 
-        expect(permissions(guest, guest_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(guest, guest_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
       end
 
       it 'allows reporters to create and delete metric images' do
-        expect(permissions(reporter, issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
-        expect(permissions(reporter, reporter_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(reporter, issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(reporter, reporter_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
       end
 
       context 'Timeline events' do
@@ -79,19 +79,19 @@ RSpec.describe IssuablePolicy, models: true do
       let_it_be(:issue) { create(:issue, project: project) }
 
       it 'disallows non-members from creating and deleting metric images' do
-        expect(permissions(non_member, issue)).to be_disallowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(non_member, issue)).to be_disallowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
       end
 
       it 'allows guests to read metric images, and create + delete in their own issues' do
         expect(permissions(guest, issue)).to be_allowed(:read_issuable_metric_image)
-        expect(permissions(guest, issue)).to be_disallowed(:upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(guest, issue)).to be_disallowed(:upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
 
-        expect(permissions(guest, guest_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(guest, guest_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
       end
 
       it 'allows reporters to create and delete metric images' do
-        expect(permissions(reporter, issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
-        expect(permissions(reporter, reporter_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(reporter, issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
+        expect(permissions(reporter, reporter_issue)).to be_allowed(:read_issuable_metric_image, :upload_issuable_metric_image, :update_issuable_metric_image, :destroy_issuable_metric_image)
       end
 
       context 'Timeline events' do