Updating CHANGES.txt for TEZ-2731 backport (rbalamohan)
Updating CHANGES.txt for TEZ-2731 backport (rbalamohan)

sidseth/tez,jth/tez,apache/tez,ueshin/apache-tez,ueshin/apache-tez,dongjiaqiang/tez,jth/tez,ChetnaChaudhari/tez,dongjiaqiang/tez,guiling/tez,ueshin/apache-tez,guiling/tez,dongjiaqiang/tez,sidseth/tez,apache/tez,ChetnaChaudhari/tez,sidseth/tez,jth/tez,guiling/tez,jth/tez,ChetnaChaudhari/tez,Parth-Brahmbhatt/tez,sidseth/tez,dongjiaqiang/tez,apache/tez,sidseth/tez,ueshin/apache-tez,Parth-Brahmbhatt/tez,ChetnaChaudhari/tez,jth/tez,guiling/tez,Parth-Brahmbhatt/tez,apache/tez,ChetnaChaudhari/tez,guiling/tez,ueshin/apache-tez,Parth-Brahmbhatt/tez,dongjiaqiang/tez,Parth-Brahmbhatt/tez,apache/tez