Turn off randomization for leak detection bots. (#145624)

dev/bots/test.dart

@@ -187,6 +187,8 @@ String get shuffleSeed {
   return _shuffleSeed!;
 }
 
+final bool _isRandomizationOff = bool.tryParse(Platform.environment['TEST_RANDOMIZATION_OFF'] ?? '') ?? false;
+
 /// When you call this, you can pass additional arguments to pass custom
 /// arguments to flutter test. For example, you might want to call this
 /// script with the parameter --local-engine=host_debug_unopt to
@@ -2471,7 +2473,7 @@ Future<void> _runFlutterTest(String workingDirectory, {
 
   final List<String> args = <String>[
     'test',
-    if (shuffleTests) '--test-randomize-ordering-seed=$shuffleSeed',
+    if (shuffleTests && !_isRandomizationOff) '--test-randomize-ordering-seed=$shuffleSeed',
     if (fatalWarnings) '--fatal-warnings',
     ...options,
     ...tags,