Fix initial Eureka instance replication delay

[yashdotdev13]

Overview

Fixes an issue where the initial Eureka instance status update can trigger an
on-demand registration before the configured initial instance info replication
delay has elapsed.

Changes

• Set the initial Eureka instance status before initializing the Eureka client.
• Prevent the initial status change from triggering an immediate on-demand
  registration.
• Added a regression test to verify that the initial status is set before
  Eureka client initialization.

Testing

• ./mvnw.cmd -pl spring-cloud-netflix-eureka-client -Dtest=EurekaServiceRegistryTests test
• ./mvnw.cmd -pl spring-cloud-netflix-eureka-client test

Results:

• EurekaServiceRegistryTests: 6/6 passed
• Eureka client module: 211/211 passed
• Checkstyle: 0 violations

Related Issue

Fixes #4109

[ryanjbaxter]

Can you look into the failing PR build?

[yashdotdev13]

I looked into the failing build. The failure is occurring in the spring-cloud-netflix-eureka-client-tls-tests module, specifically during EurekaClientSuite setup. The test fails because the Eureka client cannot connect to the dynamically started local server (Connection refused).

The changes in this PR are limited to EurekaServiceRegistry and its tests, and the targeted EurekaServiceRegistryTests pass locally. I also reproduced the relevant upstream tests successfully on their own.

I’m continuing to investigate why the TLS test server is unavailable during the full CI build.

[ryanjbaxter]

You can try and merge in main to your branch, but the CI build is passing fine
https://github.com/spring-cloud/spring-cloud-netflix/actions/runs/34174744571

[ryanjbaxter]

If I build your branch locally the same tests fail for me. If I revert your change the tests pass, so it is something in your changes that broke the tests