Pulsar Helm Chart Initialization Failure When Using Existing Secret

**Describe the bug**
The Pulsar Helm chart fails to initialize the pulsar-manager-init pod when the existingSecret feature is used. The initialization process gets stuck, preventing the pod from starting, and the CSRF token becomes unusable, leading to 404 errors during login attempts.

**To Reproduce**
Steps to reproduce the behavior:
1. Configure the Helm chart to use an existing secret
```
pulsar_manager:
admin:
existingSecret: 'some-secret-name'
```
2. Deploy the Helm chart.
3. Observe the pulsar-manager-init pod status.

**Expected behavior**
The pulsar-manager-init pod should initialize correctly, and the job should complete successfully. The CSRF token should be usable, and login requests to Pulsar Manager should not return 404 errors.

**Additional context**
This issue occurs when trying to use the existingSecret feature to avoid hardcoding credentials in values files. The initialization of the pulsar-manager-init pod fails, causing subsequent CSRF token and login requests to return 404 errors.

the pulsar-manager-init pod no longer initializes, being stuck in PodInitializing. Additionally, the job does not finish, and the CSRF token becomes unusable, resulting in 404 errors when attempting to log in to Pulsar Manager for both the CSRF token and POST login request.

Start by locating the Helm templates for the pulsar-manager-init pod and the existingSecret configuration, then reproduce the deployment with the values shown. Check why initialization remains stuck and why the CSRF token becomes unusable. Done means the init job completes, the pod starts, and Pulsar Manager login requests no longer return 404 errors.

Written by the indexing model from the issue text.