AutoConfiguredRestClientSsl overwrites configuration from HttpClientProperties

[kzander91]

This is similar to #36594 and #27360 but I'm not sure if a solution for those issues would also fix mine, so feel free to close this if you consider this to be a duplicate.

Issue: Configuration made through the spring.http.client properties is ignored if I use AutoConfiguredRestClientSsl. For example, configuration like

spring:
  http:
    client:
      redirects: dont_follow

does not work if I also have this:

@Bean
RestClientCustomizer clientCertConfigurer(RestClientSsl restClientSsl) {
    return builder -> builder.apply(restClientSsl.fromBundle("my-bundle"));
}

The reason for this is that AutoConfiguredRestClientSsl replaces the request factory and thus discards any configuration made via the spring.http.client properties:

spring-boot/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/client/AutoConfiguredRestClientSsl.java

Lines 52 to 56 in 1832852

	return (builder) -> {
	ClientHttpRequestFactorySettings settings = ClientHttpRequestFactorySettings.ofSslBundle(bundle);
	ClientHttpRequestFactory requestFactory = this.clientHttpRequestFactoryBuilder.build(settings);
	builder.requestFactory(requestFactory);
	};

For this specific issue I can work around this by removing my RestClientCustomizer and use

spring:
  http:
    client:
      redirects: dont_follow
      ssl:
        bundle: "my-bundle"

instead, but this only works in this static scenario, if I needed some more sophisticated logic to determine the SSL bundle to use at runtime, this wouldn't work.