Move HDFS-8337 to branch 2.8 in CHANGES.txt.
Move HDFS-8337 to branch 2.8 in CHANGES.txt.

(cherry picked from commit 20c03c96066752f0a7158846de4d7bc4253e83f6)

Microsoft-CISL/hadoop-prototype,intel-hadoop/hadoop,Microsoft-CISL/hadoop-prototype,satishpatil2k13/ODPI-Hadoop,Microsoft-CISL/hadoop-prototype,satishpatil2k13/ODPI-Hadoop,satishpatil2k13/ODPI-Hadoop,intel-hadoop/hadoop,Microsoft-CISL/hadoop-prototype,intel-hadoop/hadoop,MjAbuz/hadoop,intel-hadoop/hadoop,MjAbuz/hadoop,Microsoft-CISL/hadoop-prototype,MjAbuz/hadoop,satishpatil2k13/ODPI-Hadoop,Microsoft-CISL/hadoop-prototype,zrccxyb62/hadoop,satishpatil2k13/ODPI-Hadoop,zrccxyb62/hadoop,intel-hadoop/hadoop,intel-hadoop/hadoop,satishpatil2k13/ODPI-Hadoop,zrccxyb62/hadoop,MjAbuz/hadoop,MjAbuz/hadoop,satishpatil2k13/ODPI-Hadoop,zrccxyb62/hadoop,intel-hadoop/hadoop,MjAbuz/hadoop,zrccxyb62/hadoop,zrccxyb62/hadoop,MjAbuz/hadoop,zrccxyb62/hadoop,Microsoft-CISL/hadoop-prototype,satishpatil2k13/ODPI-Hadoop,Microsoft-CISL/hadoop-prototype