[SPARK-4966][YARN]The MemoryOverhead value is setted not correctly

Author: meiyoula <1039320815@qq.com>

Closes #3797 from XuTingjun/MemoryOverhead and squashes the following commits:

5a780fc [meiyoula] Update ClientArguments.scala

yarn/src/main/scala/org/apache/spark/deploy/yarn/ClientArguments.scala

@@ -39,6 +39,8 @@ private[spark] class ClientArguments(args: Array[String], sparkConf: SparkConf)
   var appName: String = "Spark"
   var priority = 0
 
+  parseArgs(args.toList)
+
   // Additional memory to allocate to containers
   // For now, use driver's memory overhead as our AM container's memory overhead
   val amMemoryOverhead = sparkConf.getInt("spark.yarn.driver.memoryOverhead",
@@ -50,7 +52,6 @@ private[spark] class ClientArguments(args: Array[String], sparkConf: SparkConf)
   private val isDynamicAllocationEnabled =
     sparkConf.getBoolean("spark.dynamicAllocation.enabled", false)
 
-  parseArgs(args.toList)
   loadEnvironmentArgs()
   validateArgs()