HIVE-29340: Restore Hive ATSHook to populate the Tez View Queries tab

This is revert of HIVE-20078

Author: Aggarwal-Raghav

common/src/java/org/apache/hadoop/hive/conf/HiveConf.java

@@ -762,6 +762,9 @@ public static enum ConfVars {
         + "threads that can be used for collection of file level statistics. If the value configured is x, then the "
         + "maximum number of threads that can be used is x multiplied by the number of available processors.  A value"
         + " of less than 1, makes stats collection sequential."),
+    ATS_HOOK_QUEUE_CAPACITY("hive.ats.hook.queue.capacity", 64,
+      "Queue size for the ATS Hook executor. If the number of outstanding submissions \n" +
+        "to the ATS executor exceed this amount, the Hive ATS Hook will not try to log queries to ATS."),
     EXEC_PARALLEL("hive.exec.parallel", false, "Whether to execute jobs in parallel"),
     EXEC_PARALLEL_THREAD_NUMBER("hive.exec.parallel.thread.number", 8,
         "How many jobs at most can be executed in parallel"),