SpringBoot Configuration properties for Statsd's buffered and step properties are missing

This PR changes to expose buffered property for StatsdConfig.

See https://github.com/micrometer-metrics/micrometer/issues/1375

Comment From: wilkinsona

Thanks, @izeye. It's a shame that we missed this. I've opened https://github.com/spring-projects/spring-boot/issues/30901 to see if we can stop if from happening again.

There is a workaround for the missing property, but it's not very elegant:

@Bean
StatsdConfig statsdConfig(StatsdProperties statsdProperties) {
    return new StatsdPropertiesConfigAdapter(statsdProperties) {

        @Override
        public boolean buffered() {
            return false;
        }

    };
}

As such, I am a bit tempted to treat this as a bug and fix it in 2.5.x. Flagging for team attention to see what everyone else thinks.

Comment From: scottfrederick

I think it's reasonable to consider this a bug of omission.

Comment From: wilkinsona

I've started looking at implementing something for #30901 and it looks like we're missing a configuration property for step as well. WDYT, @izeye? Does it make sense to have a configuration property for it?

Comment From: izeye

@wilkinsona I don't have much experience working with StatsD, but it seems to have been missed unintentionally, too and it sounds reasonable to align configurability level with its corresponding meter registry configuration.

/cc @shakuzen

Comment From: shakuzen

Statsd's step makes sense to expose as a configuration property and I suspect we just missed it.

Comment From: wilkinsona

Thanks, @shakuzen. @izeye, do you have time to update this PR to add step as well?

Comment From: izeye

@wilkinsona Sure, I pushed ccbe758 for it.

Comment From: snicoll

Thanks again @izeye