CLDR-14408 improve FE test timeouts (#1377)

per shellscape/mocha-chrome#32 (comment)

Author: srl295

tools/cldr-apps/js/package.json

@@ -7,7 +7,7 @@
     "build-test": "webpack --config webpack-test.config.js",
     "test": "npm run nonbrowser-test && npm run browser-test",
     "nonbrowser-test": "mocha --require esm --reporter spec test/nonbrowser/test-*.js",
-    "browser-test": "npm run build-test && mocha-chrome test/Test.html",
+    "browser-test": "npm run build-test && mocha-chrome test/Test.html --chrome-launcher.connectionPollInterval=2000 --chrome-launcher.maxConnectionRetries=300",
     "lint": "exit 0",
     "build": "webpack",
     "watch": "webpack watch"