[fix](regression)Fix unstable delta rows case. (#43928)

### What problem does this PR solve?

Fix unstable delta rows case.
This case assume the table row count is not reported during the
execution, but in sometimes the row count may reported, which will cause
the case fail.

regression-test/suites/nereids_p0/delta_row/delta_row.groovy

@@ -42,14 +42,34 @@ suite("delta_row") {
     sql "set global enable_auto_analyze=false;"
 
     sql "insert into t values (10, 'c');"
-    explain {
-        sql "physical plan select * from t where k > 6"
-        contains("stats=0.5,")
-        contains("stats=5(1)")
-        notContains("stats=0,")
-        notContains("stats=4 ")
+    def result = sql """explain physical plan select * from t where k > 6"""
+    logger.info("result:" + result)
+    def stringResult = ""
+    for (int i = 0; i < result.size(); i++) {
+        stringResult += result[i]
+    }
+    logger.info("stringResult:" + stringResult)
+    if (stringResult.contains("stats=5(1)")) {
+        logger.info("rows not reported, test analyze rows + delta rows")
+        assertTrue(stringResult.contains("stats=0.5,"))
+        assertFalse(stringResult.contains("stats=0,"))
+        assertFalse(stringResult.contains("stats=4 "))
+    } else {
+        logger.info("rows reported, test use reported rows.")
+        result = sql """show index stats t t"""
+        logger.info("index stats: " + result)
+        assertEquals(1, result.size())
+        assertNotEquals("-1", result[0][4])
+    }
+//    explain {
+//        sql "physical plan select * from t where k > 6"
+//        contains("stats=0.5,")
+//        contains("stats=5(1)")
+//        notContains("stats=0,")
+//        notContains("stats=4 ")
+// cost = 5.00002
 // PhysicalResultSink[75] ( outputExprs=[k#0, v#1] )
 // +--PhysicalFilter[72]@1 ( stats=0.5, predicates=(k#0 > 6) )
 //    +--PhysicalOlapScan[t]@0 ( stats=5(1) )
-    }
-}
+}
+