YARN-6480. Timeout is too aggressive for TestAMRestart.testPreemptedAMRestartOnRMRestart. Contributed by Eric Badger

(cherry picked from commit 416880550214e58f2284a045ad0c96ba4aa78ea8)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/applicationsmanager/TestAMRestart.java

@@ -480,7 +480,7 @@ public class TestAMRestart {
   // Test RM restarts after AM container is preempted, new RM should not count
   // AM preemption failure towards the max-retry-account and should be able to
   // re-launch the AM.
-  @Test(timeout = 20000)
+  @Test(timeout = 60000)
   public void testPreemptedAMRestartOnRMRestart() throws Exception {
     YarnConfiguration conf = new YarnConfiguration();
     conf.setClass(YarnConfiguration.RM_SCHEDULER, CapacityScheduler.class,