[ISSUE-451][Improvement] Read HDFS data files with random sequence to…

… distribute pressure (#452)

### What changes were proposed in this pull request?
[Improvement] Read HDFS data files with random sequence to distribute pressure #452

### Why are the changes needed?
In PR #396 to support concurrently writing single partition's data into multiple HDFS files, it's better to randomly read HDFS data files to distribute stress in client side.

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
Existing UTs

storage/src/main/java/org/apache/uniffle/storage/handler/impl/HdfsClientReadHandler.java

@@ -18,8 +18,9 @@
 package org.apache.uniffle.storage.handler.impl;
 
 import java.io.FileNotFoundException;
-import java.util.Comparator;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import com.google.common.collect.Lists;
 import org.apache.hadoop.conf.Configuration;
@@ -143,7 +144,10 @@ protected void init(String fullShufflePath) {
           LOG.warn("Can't create ShuffleReaderHandler for " + filePrefix, e);
         }
       }
-      readHandlers.sort(Comparator.comparing(HdfsShuffleReadHandler::getFilePrefix));
+      Collections.shuffle(readHandlers);
+      LOG.info("Reading order of HDFS files with name prefix: {}",
+          readHandlers.stream().map(x -> x.filePrefix).collect(Collectors.toList())
+      );
     }
   }