Extract constant for number of siblings per block

Signed-off-by: Matt Hess <[email protected]>

Author: mhess-swl

hedera-node/hedera-app/src/main/java/com/hedera/node/app/blocks/BlockStreamManager.java

@@ -29,6 +29,7 @@
  */
 public interface BlockStreamManager extends BlockRecordInfo, StateHashedListener {
     Bytes ZERO_BLOCK_HASH = Bytes.wrap(new byte[48]);
+    int NUM_SIBLINGS_PER_BLOCK = 4;
 
     /**
      * The types of work that may be identified as pending within a block.

hedera-node/hedera-app/src/main/java/com/hedera/node/app/blocks/impl/streaming/FileBlockItemWriter.java

@@ -2,6 +2,7 @@
 package com.hedera.node.app.blocks.impl.streaming;
 
 import static com.hedera.hapi.util.HapiUtils.asAccountString;
+import static com.hedera.node.app.blocks.BlockStreamManager.NUM_SIBLINGS_PER_BLOCK;
 import static com.swirlds.common.io.utility.FileUtils.getAbsolutePath;
 import static java.util.Objects.requireNonNull;
 
@@ -243,7 +244,7 @@ public static List<OnDiskPendingBlock> loadContiguousPendingBlocks(
             // Verify old proofs without block timestamp or sibling hashes are skipped
             if (pendingProof.blockTimestamp() == null
                     || Objects.equals(pendingProof.blockTimestamp(), Timestamp.DEFAULT)
-                    || pendingProof.siblingHashesFromPrevBlockRoot().size() != 4) {
+                    || pendingProof.siblingHashesFromPrevBlockRoot().size() != NUM_SIBLINGS_PER_BLOCK) {
                 logger.warn(
                         "Pending proof metadata from {} is missing required fields (not considering remaining - {})",
                         proofJson.toPath(),