Add metrics for failed deliveries to Grafana dashboard (#11481)

etc/grafana/dashboards/overview.json

@@ -5732,6 +5732,79 @@
       "title": "Engine API getPayloadBodies Latency",
       "type": "timeseries"
     },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "${DS_PROMETHEUS}"
+      },
+      "description": "Counts the number of failed response deliveries due to client request termination.",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 0,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": false,
+            "stacking": {
+              "mode": "none"
+            }
+          },
+          "unit": "none"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 24,
+        "x": 0,
+        "y": 198
+      },
+      "id": 213,  
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "list",
+          "placement": "bottom",
+          "showLegend": true
+        },
+        "tooltip": {
+          "mode": "single",
+          "sort": "none"
+        }
+      },
+      "targets": [
+        {
+          "expr": "consensus_engine_beacon_failed_new_payload_response_deliveries{instance=~\"$instance\"}",
+          "legendFormat": "Failed NewPayload Deliveries",
+          "refId": "A"
+        },
+        {
+          "expr": "consensus_engine_beacon_failed_forkchoice_updated_response_deliveries{instance=~\"$instance\"}",
+          "legendFormat": "Failed ForkchoiceUpdated Deliveries",
+          "refId": "B"
+        }
+      ],
+      "title": "Failed Engine API Response Deliveries",
+      "type": "timeseries"
+    },
     {
       "collapsed": false,
       "gridPos": {