Description of problem:

4.15.0-0.nightly-2024-03-04-212436 cluster, cluster admin login admin console, and go to "Observe -> Alerting -> Silences" page, click "Create silence" button, empty value for Creator. "kube:admin" is not automatically filled to the field. Set the required values for the silence then create silence, there is error

An error occurred
createdBy in body is required 

see picture: https://drive.google.com/file/d/1taP8z1CPdchinzuyuIRaH_91zSsdSQqf/view?usp=drive_link 

no such issue for 4.13/4.14 and previous 4.15 version, example: 4.15.0-0.nightly-2024-02-22-193834, "kube:admin" is automatically added to Creator field after clicked "Create silence" button.

4.15/4.16

Version-Release number of selected component (if applicable):

4.15.0-0.nightly-2024-03-04-212436

How reproducible:

4.15 and above version

Steps to Reproduce:

1. see the description

Actual results:

empty value for Creator when clicked "Create silence" button on silences page

Expected results:

auto filled