Changes in "vaadin.devmode.hostsAllowed" is not picked up even on server restart.

[sujoykd]

Description of the bug

In v24.3.2, changes in vaadin.devmode.hostsAllowed from application.properties is not picked up even on server restart.

This seems to be related to #18318 since the deploymentConfiguration is read from the session here - https://github.com/vaadin/flow/blob/main/flow-server/src/main/java/com/vaadin/flow/server/communication/IndexHtmlRequestHandler.java#L95

Expected behavior

Changes in properties should be picked up every time on server restart

Minimal reproducible example

1. Download sample project from start.vaadin.com with 24.3.2 & Spring boot
2. Make changes in vaadin.devmode.hostsAllowed, restart app and check if the changes work.

Repeat step 2 multiple times to observe that changes dont work on server restart.

Versions

• Vaadin / Flow version: 24.3.2
• Java version: 17

[tepi]

Might be related to #18318 since the code referenced in the original description fetches the configuration from session - so if the session is persisted over the restart, the value of vaadin.devmode.hostsAllowed will definitely not be updated currently.

[tepi]

In flow-client we have 21 usages of com.vaadin.flow.server.VaadinSession#getConfiguration and 32 usages of com.vaadin.flow.server.VaadinService#getDeploymentConfiguration. Unfortunately there seems to be not much logic on when either of these methods is used, e.g. IndexHtmlRequestHandler is using both in different parts of the code to check if production mode is enabled.

Maybe it could be possible for us to change the 21 usages of the session-tied configuration to use the method from VaadinService. Although not sure if this change would break something for some use case.

@mshabarov Any thoughts?