Mask host position in the plan of testInternalItemAccessOnStructs

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteExplainIT.java

@@ -1472,11 +1472,12 @@ public void testGeoIpPushedInAgg() throws IOException {
   public void testInternalItemAccessOnStructs() throws IOException {
     String expected = loadExpectedPlan("access_struct_subfield_with_item.yaml");
     assertYamlEqualsIgnoreId(
-        expected,
+        // The position of host in the scanned table is different in backport (no pushdown). Therefore, we mask all positions with $*
+        expected.replaceAll("\\$t?\\d+", "\\$*"),
         explainQueryYaml(
             String.format(
                 "source=%s | eval info = geoip('dummy-datasource', host) | fields host, info,"
                     + " info.dummy_sub_field",
-                TEST_INDEX_WEBLOGS)));
+                TEST_INDEX_WEBLOGS)).replaceAll("\\$t?\\d+", "\\$*"));
   }
 }