auto start server

Summary:
This will automatically invoke the "Start" button if Flipper detect it is offline, to automate that step. It will do so only once

(safe for the reload logic that also triggers on server errors, not sure if that was intentionally?)

Reviewed By: lblasa

Differential Revision: D50074673

fbshipit-source-id: 2c11e80429a2c4ed0e43e62cb2f6057fad5eb410

desktop/static/offline.html

@@ -137,7 +137,6 @@
       setTimeout(() => {
         button.disabled = false;
         button.value = 'Start';
-
       }, 30 * 10000);
     }
 
@@ -148,18 +147,24 @@
       window.location.reload();
     });
 
+    let autoStarted = false;
+
     // Check if the server is responding & reload the page if it is.
     // This handles the case when the device is online, but the server
     // is offline or misbehaving.
     async function checkNetworkAndReload() {
       try {
         const response = await fetch('.');
-        if (response.status >= 200 && response.status < 500) {
+        if (response.status === 200) {
           window.location.reload();
           return;
         }
       } catch {
-        // Unable to connect to the server, ignore.
+        // trigger submit button automatically, but only once
+        if (!autoStarted) {
+          autoStarted = true;
+          document.getElementById("submit").click();
+        }
       }
       window.setTimeout(checkNetworkAndReload, 2500);
     }