Clean up update server

Reviewed By: lblasa

Differential Revision: D48433744

fbshipit-source-id: 749868e00e17af02040a8e2c164631e295deae65

desktop/patches/metro+0.70.2.patch

@@ -0,0 +1,26 @@
+diff --git a/node_modules/metro/src/index.js b/node_modules/metro/src/index.js
+index 1c3a58e..96c7376 100644
+--- a/node_modules/metro/src/index.js
++++ b/node_modules/metro/src/index.js
+@@ -115,8 +115,6 @@ const createConnectMiddleware = async function (config, options) {
+           wss.handleUpgrade(request, socket, head, (ws) => {
+             wss.emit("connection", ws, request);
+           });
+-        } else {
+-          socket.destroy();
+         }
+       });
+     },
+diff --git a/node_modules/metro/src/lib/getPreludeCode.js b/node_modules/metro/src/lib/getPreludeCode.js
+index 56780d7..7da26d1 100644
+--- a/node_modules/metro/src/lib/getPreludeCode.js
++++ b/node_modules/metro/src/lib/getPreludeCode.js
+@@ -14,7 +14,7 @@ function getPreludeCode({ extraVars, isDev, globalPrefix }) {
+     "__BUNDLE_START_TIME__=this.nativePerformanceNow?nativePerformanceNow():Date.now()",
+     `__DEV__=${String(isDev)}`,
+     ...formatExtraVars(extraVars),
+-    "process=this.process||{}",
++    "process=process||this.process||global.process||{}",
+     `__METRO_GLOBAL_PREFIX__='${globalPrefix}'`,
+   ];
+   return `var ${vars.join(",")};${processEnv(