[fix][ml] Return 1 when bytes size is 0 or negative for entry count estimation (#24131)

(cherry picked from commit 82d3902)

Author: lhotari

Diff for: managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/EntryCountEstimator.java

@@ -72,8 +72,8 @@ static int internalEstimateEntryCountByBytesSize(int maxEntries, long maxSizeByt
                                                      Long lastLedgerId, long lastLedgerTotalEntries,
                                                      long lastLedgerTotalSize) {
         if (maxSizeBytes <= 0) {
-            // If the specified maximum size is invalid (e.g., non-positive), return 0
-            return 0;
+            // If the specified maximum size is invalid (e.g., non-positive), return 1
+            return 1;
         }
 
         // If the maximum size is Long.MAX_VALUE, return the maximum number of entries

Diff for: managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/EntryCountEstimatorTest.java

@@ -82,7 +82,13 @@ private int estimateEntryCountByBytesSize(long maxSizeBytes) {
     @Test
     public void testZeroMaxSize() {
         int result = estimateEntryCountByBytesSize(0);
-        assertEquals(result, 0, "Should return 0 when max size is 0");
+        assertEquals(result, 1, "Should return 1 when max size is 0");
+    }
+
+    @Test
+    public void testNegativeMaxSize() {
+        int result = estimateEntryCountByBytesSize(-1);
+        assertEquals(result, 1, "Should return 1 when max size is negative");
     }
 
     @Test