Do test_getStackTraces last for test 129

Doing this check last leaves time for the heap task daemon to call
TaskProcessor::RunAllTasks. This should hopefully fix the flakiness
of test 129 during startup.

Test: test-art-host-run-test

Bug: 34342857
Change-Id: I85f8d78083092df802728c59a4c86f63be8d949a
diff --git a/test/129-ThreadGetId/src/Main.java b/test/129-ThreadGetId/src/Main.java
index 6ba01ff..4e48e0e 100644
--- a/test/129-ThreadGetId/src/Main.java
+++ b/test/129-ThreadGetId/src/Main.java
@@ -23,7 +23,6 @@
 
     public static void main(String[] args) throws Exception {
         final Thread[] threads = new Thread[numberOfThreads];
-        test_getStackTraces();
         for (int t = 0; t < threads.length; t++) {
             threads[t] = new Thread(new Main());
             threads[t].start();
@@ -31,6 +30,9 @@
         for (Thread t : threads) {
             t.join();
         }
+        // Do this test after the other part to leave some time for the heap task daemon to start
+        // up.
+        test_getStackTraces();
         System.out.println("Finishing");
     }