Use isPWA utility function instead

Summary: As a follow-up from the utility created on the previous diff

Reviewed By: aigoncharov

Differential Revision: D50885337

fbshipit-source-id: 6bc0c942b3d96eb020ec15395f34d5794ba2ae15

desktop/flipper-ui-browser/src/index.tsx

@@ -15,6 +15,7 @@ import {
 import {init as initLogger} from './fb-stubs/Logger';
 import {initializeRenderHost} from './initializeRenderHost';
 import {createFlipperServer, FlipperServerState} from 'flipper-server-client';
+import {isPWA} from 'flipper-ui-core';
 
 const loadingContainer = document.getElementById('loading');
 if (loadingContainer) {
@@ -151,7 +152,7 @@ start().catch((e) => {
   logger.track('success-rate', 'flipper-ui-browser-started', {
     value: 0,
     error: getStringFromErrorLike(e),
-    pwa: window.matchMedia('(display-mode: standalone)').matches,
+    pwa: isPWA(),
   });
   window.flipperShowMessage?.('Failed to start UI with error: ' + e);
 });