Merge bitcoin#28831: test: Avoid intermittent failures in feature_init

44445ae test: Avoid intermittent failures in feature_init (MarcoFalke)

Pull request description:

  The code not only modifies block dat files, but also leveldb files, which may be of smaller size. Such corruption may not force leveldb to abort, according to the intermittent test failures.

  Fix the intermittent test failures by reverting bitcoin@5ab6419 .

ACKs for top commit:
  kevkevinpal:
    lgtm ACK [44445ae](bitcoin@44445ae)
  fjahr:
    ACK 44445ae
  theStack:
    ACK 44445ae

Tree-SHA512: 8084e4aeb8a976c1706a1898d7854c55d0c4ec7b5a08f65f97ffc173c935f9b0e0c1caef7be1538a458e4c018f7bd1948173349ec76ca48bc4013a63f284bb0f

Author: fanquake

test/functional/feature_init.py

@@ -1,11 +1,10 @@
 #!/usr/bin/env python3
-# Copyright (c) 2021 The Bitcoin Core developers
+# Copyright (c) 2021-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Stress tests related to node initialization."""
 import os
 from pathlib import Path
-from random import randint
 import shutil
 
 from test_framework.test_framework import BitcoinTestFramework, SkipTest
@@ -139,8 +138,8 @@ def check_clean_start():
                     # Since the genesis block is not checked by -checkblocks, the
                     # perturbation window must be chosen such that a higher block
                     # in blk*.dat is affected.
-                    tf.seek(randint (150, 15000))
-                    tf.write(b'1' * randint(20, 2000))
+                    tf.seek(150)
+                    tf.write(b"1" * 200)
 
             start_expecting_error(err_fragment)