HDFS-16579. Fix build failure for TestBlockManager on branch-3.2 (#4310)

Reviewed-by: Akira Ajisaka <aajisaka@apache.org>
Signed-off-by: Takanobu Asanuma <tasanuma@apache.org>

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockManager.java

@@ -60,6 +60,7 @@ import org.apache.hadoop.hdfs.server.namenode.CachedBlock;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.hdfs.server.namenode.INodeFile;
 import org.apache.hadoop.hdfs.server.namenode.INodeId;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
 import org.apache.hadoop.hdfs.server.namenode.TestINodeFile;
 import org.apache.hadoop.hdfs.server.namenode.ha.HAContext;