Update code samples [skip ci]

Author: github-actions[bot]

snippets/samples/code_samples_export_post_1.mdx

@@ -13,4 +13,11 @@ curl \
     }
   }'
 ```
+
+```java Java
+Map<String, ExportIndexFilter> indexes = new HashMap<>();
+indexes.put("*", ExportIndexFilter.builder().overrideSettings(true).build());
+ExportRequest request = ExportRequest.builder().url("TARGET_INSTANCE_URL").indexes(indexes).build();
+client.export(request);
+```
 </CodeGroup>