use old Edge-compatible JavaScript in index.html (#83732)

packages/flutter_tools/templates/app/web/index.html.tmpl

@@ -67,7 +67,7 @@
             if (!reg.active && (reg.installing || reg.waiting)) {
               // No active web worker and we have installed or are installing
               // one for the first time. Simply wait for it to activate.
-              waitForActivation(reg.installing ?? reg.waiting);
+              waitForActivation(reg.installing || reg.waiting);
             } else if (!reg.active.scriptURL.endsWith(serviceWorkerVersion)) {
               // When the app updates the serviceWorkerVersion changes, so we
               // need to ask the service worker to update.