Back out "Back out Electron 7.1.1/7.1.2 upgrades"

Summary:
Original commit changeset: 05d13aca7145

Attempt to upgrade `electron` as it instacrashed; `electron-builder` version 22.1.0 didn't sign package correctly and caused the instacrash,

Reduced the version to 21.2.0 (latest).

Reviewed By: passy, nikoant

Differential Revision: D18954671

fbshipit-source-id: bc2dbd4fec9afb51d9a535974651b13d195407b4

src/dispatcher/application.tsx

@@ -7,7 +7,7 @@
  * @format
  */
 
-import {remote, ipcRenderer} from 'electron';
+import {remote, ipcRenderer, IpcRendererEvent} from 'electron';
 import {toggleAction} from '../reducers/application';
 import {setStaticView} from '../reducers/connections';
 import {Store} from '../reducers/index.js';
@@ -68,7 +68,7 @@ export default (store: Store, logger: Logger) => {
 
   ipcRenderer.on(
     'flipper-protocol-handler',
-    (_event: string, query: string) => {
+    (_event: IpcRendererEvent, query: string) => {
       const uri = new URL(query);
       if (query.startsWith('flipper://import')) {
         const {search} = new URL(query);
@@ -117,11 +117,14 @@ export default (store: Store, logger: Logger) => {
     },
   );
 
-  ipcRenderer.on('open-flipper-file', (_event: string, url: string) => {
-    tryCatchReportPlatformFailures(() => {
-      return importFileToStore(url, store);
-    }, `${IMPORT_FLIPPER_TRACE_EVENT}:Deeplink`);
-  });
+  ipcRenderer.on(
+    'open-flipper-file',
+    (_event: IpcRendererEvent, url: string) => {
+      tryCatchReportPlatformFailures(() => {
+        return importFileToStore(url, store);
+      }, `${IMPORT_FLIPPER_TRACE_EVENT}:Deeplink`);
+    },
+  );
 
   if (process.env.FLIPPER_PORTS) {
     const portOverrides = parseFlipperPorts(process.env.FLIPPER_PORTS);

src/dispatcher/notifications.tsx

@@ -12,8 +12,8 @@ import {Logger} from '../fb-interfaces/Logger';
 import {PluginNotification} from '../reducers/notifications';
 import {FlipperPlugin, FlipperDevicePlugin} from '../plugin';
 import isHeadless from '../utils/isHeadless';
-import {ipcRenderer} from 'electron';
 import {setStaticView} from '../reducers/connections';
+import {ipcRenderer, IpcRendererEvent} from 'electron';
 import {
   setActiveNotifications,
   updatePluginBlacklist,
@@ -39,6 +39,7 @@ export default (store: Store, logger: Logger) => {
   ipcRenderer.on(
     'notificationEvent',
     (
+      _event: IpcRendererEvent,
       _e: Error,
       eventName: NotificationEvents,
       pluginNotification: PluginNotification,