CV2-4233 add retry looper for alegre requests that intermittently fail

app/models/concerns/alegre_v2.rb

@@ -231,14 +231,24 @@ def parse_similarity_results(project_media, field, results, relationship_type)
       }.reject{ |k,_| k == project_media.id }]
     end
 
+    def safe_get_sync(project_media, field, threshold)
+      response = get_sync(project_media, field, threshold)
+      retries = 0
+      while (response == nil or response["result"] == nil) and retries < 3
+        response = get_sync(project_media, field, threshold)
+        retries += 1
+      end
+      response
+    end
+
     def get_items(project_media, field, confirmed=false)
       relationship_type = confirmed ? Relationship.confirmed_type : Relationship.suggested_type
       type = get_type(project_media)
       threshold = get_per_model_threshold(project_media, Bot::Alegre.get_threshold_for_query(type, project_media, confirmed))
       parse_similarity_results(
         project_media,
         field,
-        get_sync(project_media, field, threshold)["result"],
+        safe_get_sync(project_media, field, threshold)["result"],
         relationship_type
       )
     end

test/models/bot/alegre_v2_test.rb

@@ -283,6 +283,13 @@ def teardown
     assert_equal JSON.parse(Bot::Alegre.get_sync(pm1).to_json), JSON.parse(response.to_json)
   end
 
+  test "should safe_get_sync" do
+    pm1 = create_project_media team: @team, media: create_uploaded_audio
+    response = {}
+    WebMock.stub_request(:post, "#{CheckConfig.get('alegre_host')}/similarity/sync/audio").with(body: {:doc_id=>Bot::Alegre.item_doc_id(pm1), :context=>{:team_id=>pm1.team_id, :project_media_id=>pm1.id, :has_custom_id=>true}, :url=>Bot::Alegre.media_file_url(pm1)}).to_return(body: response.to_json)
+    assert_equal Bot::Alegre.safe_get_sync(pm1), {}
+  end
+
   test "should run delete request" do
     pm1 = create_project_media team: @team, media: create_uploaded_audio
     response = {"requested"=>