Revert changes to grep

Author: DonJayamanne

src/test/index.ts

@@ -12,7 +12,7 @@ process.env.IS_MULTI_ROOT_TEST = IS_MULTI_ROOT_TEST.toString();
 // If running on CI server and we're running the debugger tests, then ensure we only run debug tests.
 // We do this to ensure we only run debugger test, as debugger tests are very flaky on CI.
 // So the solution is to run them separately and first on CI.
-const grep = IS_CI_SERVER && IS_CI_SERVER_TEST_DEBUGGER ? 'Debug' : 'FileSystem';
+const grep = IS_CI_SERVER && IS_CI_SERVER_TEST_DEBUGGER ? 'Debug' : undefined;
 
 const testFilesSuffix = process.env.TEST_FILES_SUFFIX;