fix flakiness

Author: idegtiarenko

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/RequestIndexFilteringTestCase.java

@@ -204,12 +204,26 @@ public void testIndicesDontExist() throws IOException {
         ResponseException e = expectThrows(ResponseException.class, () -> runEsql(timestampFilter("gte", "2020-01-01").query(from("foo"))));
         assertEquals(400, e.getResponse().getStatusLine().getStatusCode());
         assertThat(e.getMessage(), containsString("verification_exception"));
-        assertThat(e.getMessage(), anyOf(containsString("Unknown index [foo]"), containsString("Unknown index [*:foo]")));
+        assertThat(
+            e.getMessage(),
+            anyOf(
+                containsString("Unknown index [foo]"),
+                containsString("Unknown index [*:foo]"),
+                containsString("Unknown index [remote_cluster:foo]")
+            )
+        );
 
         e = expectThrows(ResponseException.class, () -> runEsql(timestampFilter("gte", "2020-01-01").query(from("foo*"))));
         assertEquals(400, e.getResponse().getStatusLine().getStatusCode());
         assertThat(e.getMessage(), containsString("verification_exception"));
-        assertThat(e.getMessage(), anyOf(containsString("Unknown index [foo*]"), containsString("Unknown index [*:foo*]")));
+        assertThat(
+            e.getMessage(),
+            anyOf(
+                containsString("Unknown index [foo*]"),
+                containsString("Unknown index [*:foo*]"),
+                containsString("Unknown index [remote_cluster:foo*]")
+            )
+        );
 
         e = expectThrows(ResponseException.class, () -> runEsql(timestampFilter("gte", "2020-01-01").query("FROM foo, test1")));
         assertEquals(404, e.getResponse().getStatusLine().getStatusCode());