Update Grafana files

Author: ebattat

benchmark_runner/grafana/perf/dashboard.json

@@ -1256,6 +1256,10 @@
                            "index": 332,
                            "text": "4.16.18"
                         },
+                        "41619": {
+                           "index": 335,
+                           "text": "4.16.19"
+                        },
                         "4162": {
                            "index": 284,
                            "text": "4.16.2"