[SPARK-12281][CORE] Fix a race condition when reporting ExecutorState in the shutdown hook

1. Make sure workers and masters exit so that no worker or master will still be running when triggering the shutdown hook.
2. Set ExecutorState to FAILED if it's still RUNNING when executing the shutdown hook.

This should fix the potential exceptions when exiting a local cluster
```
java.lang.AssertionError: assertion failed: executor 4 state transfer from RUNNING to RUNNING is illegal
	at scala.Predef$.assert(Predef.scala:179)
	at org.apache.spark.deploy.master.Master$$anonfun$receive$1.applyOrElse(Master.scala:260)
	at org.apache.spark.rpc.netty.Inbox$$anonfun$process$1.apply$mcV$sp(Inbox.scala:116)
	at org.apache.spark.rpc.netty.Inbox.safelyCall(Inbox.scala:204)
	at org.apache.spark.rpc.netty.Inbox.process(Inbox.scala:100)
	at org.apache.spark.rpc.netty.Dispatcher$MessageLoop.run(Dispatcher.scala:215)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

java.lang.IllegalStateException: Shutdown hooks cannot be modified during shutdown.
	at org.apache.spark.util.SparkShutdownHookManager.add(ShutdownHookManager.scala:246)
	at org.apache.spark.util.ShutdownHookManager$.addShutdownHook(ShutdownHookManager.scala:191)
	at org.apache.spark.util.ShutdownHookManager$.addShutdownHook(ShutdownHookManager.scala:180)
	at org.apache.spark.deploy.worker.ExecutorRunner.start(ExecutorRunner.scala:73)
	at org.apache.spark.deploy.worker.Worker$$anonfun$receive$1.applyOrElse(Worker.scala:474)
	at org.apache.spark.rpc.netty.Inbox$$anonfun$process$1.apply$mcV$sp(Inbox.scala:116)
	at org.apache.spark.rpc.netty.Inbox.safelyCall(Inbox.scala:204)
	at org.apache.spark.rpc.netty.Inbox.process(Inbox.scala:100)
	at org.apache.spark.rpc.netty.Dispatcher$MessageLoop.run(Dispatcher.scala:215)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
```

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #10269 from zsxwing/executor-state.

core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala

@@ -75,6 +75,8 @@ class LocalSparkCluster(
     // Stop the workers before the master so they don't get upset that it disconnected
     workerRpcEnvs.foreach(_.shutdown())
     masterRpcEnvs.foreach(_.shutdown())
+    workerRpcEnvs.foreach(_.awaitTermination())
+    masterRpcEnvs.foreach(_.awaitTermination())
     masterRpcEnvs.clear()
     workerRpcEnvs.clear()
   }

core/src/main/scala/org/apache/spark/deploy/master/Master.scala

@@ -257,9 +257,8 @@ private[deploy] class Master(
           exec.state = state
 
           if (state == ExecutorState.RUNNING) {
-            if (oldState != ExecutorState.LAUNCHING) {
-              logWarning(s"Executor $execId state transfer from $oldState to RUNNING is unexpected")
-            }
+            assert(oldState == ExecutorState.LAUNCHING,
+              s"executor $execId state transfer from $oldState to RUNNING is illegal")
             appInfo.resetRetryCount()
           }
 

core/src/main/scala/org/apache/spark/deploy/worker/ExecutorRunner.scala

@@ -71,6 +71,11 @@ private[deploy] class ExecutorRunner(
     workerThread.start()
     // Shutdown hook that kills actors on shutdown.
     shutdownHook = ShutdownHookManager.addShutdownHook { () =>
+      // It's possible that we arrive here before calling `fetchAndRunExecutor`, then `state` will
+      // be `ExecutorState.RUNNING`. In this case, we should set `state` to `FAILED`.
+      if (state == ExecutorState.RUNNING) {
+        state = ExecutorState.FAILED
+      }
       killProcess(Some("Worker shutting down")) }
   }