Wait longer for the vmservice out file to appear (#103513)

An hour is likely longer than the CI timeout.

Fixes flutter/flutter#103504

dev/devicelab/lib/tasks/perf_tests.dart

@@ -1794,17 +1794,17 @@ class _UnzipListEntry {
   final String path;
 }
 
-/// Wait for up to 400 seconds for the file to appear.
+/// Wait for up to 1 hour for the file to appear.
 Future<File> waitForFile(String path) async {
-  for (int i = 0; i < 20; i += 1) {
+  for (int i = 0; i < 180; i += 1) {
     final File file = File(path);
     print('looking for ${file.path}');
     if (file.existsSync()) {
       return file;
     }
     await Future<void>.delayed(const Duration(seconds: 20));
   }
-  throw StateError('Did not find vmservice out file after 400 seconds');
+  throw StateError('Did not find vmservice out file after 1 hour');
 }
 
 String? _findIosAppInBuildDirectory(String searchDirectory) {