MAPREDUCE-7311. Clear filesystem statistics after tests in TestTaskProgressReporter (#2500)

Co-authored-by: Zhengxi Li <zli89@illinois.edu>

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapred/TestTaskProgressReporter.java

@@ -34,6 +34,7 @@ import org.apache.hadoop.mapreduce.MRConfig;
 import org.apache.hadoop.mapreduce.MRJobConfig;
 import org.apache.hadoop.mapreduce.checkpoint.TaskCheckpointID;
 import org.apache.hadoop.util.ExitUtil;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -179,6 +180,11 @@ public class TestTaskProgressReporter {
     }
   }
 
+  @After
+  public void cleanup() {
+    FileSystem.clearStatistics();
+  }
+
   @Test(timeout=60000)
   public void testScratchDirSize() throws Exception {
     String tmpPath = TEST_DIR + "/testBytesWrittenLimit-tmpFile-"