Provide explicit order for Neo4j observation customizer

[injectives]

At present, the neo4jObservationCustomizer has an effective Ordered.LOWEST_PRECEDENCE, meaning that it goes last in Neo4jAutoConfiguration:

configBuilderCustomizers.orderedStream().toList()
...
customizers.forEach((customizer) -> customizer.customize(builder));

This update sets its order to Ordered.HIGHEST_PRECEDENCE, meaning that a user-defined ConfigBuilderCustomizer can effectively override it.

As an example, this is useful when user wants to customize MicrometerObservationProvider as it actually has some optional properties that may be useful. Here is an example:

@Bean
ConfigBuilderCustomizer observationCustomizer(ObservationRegistry observationRegistry) {
    return configBuilder -> {
        var observationProvider = MicrometerObservationProvider.builder(observationRegistry)
                .alwaysIncludeQuery(true)
                .includeQueryParameters(true)
                .includeUrlScheme(true)
                .includeUrlTemplate(true)
                .requestHeaderPredicate(name -> true)
                .responseHeaderPredicate(name -> true)
                .build();
        configBuilder.withObservationProvider(observationProvider);
    };
}

[injectives]

@snicoll, sorry to ping you directly. Just came across this during my testing and thought it might be useful to submit a PR.

[snicoll]

@injectives thanks for the PR. please amend your commit with -s as the DCO check is failing at the moment.

[injectives]

@injectives thanks for the PR. please amend your commit with -s as the DCO check is failing at the moment.

Thanks! Done 👍

[wilkinsona]

I wonder if we should use 0 for the order so that user-provided customizers can go before or after it.

[snicoll]

@wilkinsona Yes, my plan was to polish the PR to use 0. In this case, the method replaces the whole implementation so it's likely to run after. But for consistency with other customizer I'd put it at 0 anyways (plus the content of the customizer could change in the future).

[injectives]

I wonder if we should use 0 for the order so that user-provided customizers can go before or after it.

There is probably no effective benefit in this as ConfigBuilder#withObservationProvider simply overrides the previous value with a new one. If user defines something, I suspect they would never want the default one to take precedence.

Having said this, please feel free to polish as you see fit.