HDDS-14015. Delete older snapshot checkpoint dirs under the snapshot content lock (#9380)

Author: swamirishi

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/snapshot/defrag/SnapshotDefragService.java

@@ -613,10 +613,10 @@ private boolean checkAndDefragSnapshot(SnapshotChainManager chainManager, UUID s
         checkpointMetadataManager = null;
         // Switch the snapshot DB location to the new version.
         previousVersion  = atomicSwitchSnapshotDB(snapshotId, checkpointLocation);
+        omSnapshotManager.deleteSnapshotCheckpointDirectories(snapshotId, previousVersion);
       } finally {
         snapshotContentLocks.releaseLock();
       }
-      omSnapshotManager.deleteSnapshotCheckpointDirectories(snapshotId, previousVersion);
     } finally {
       if (checkpointMetadataManager != null) {
         checkpointMetadataManager.close();