Autoscaler doesn't update the CR metrics change in memory correspondingly

### 🐛 Describe the bug


reproduce steps
1. define one metric name
2. update metric metric name and apply the cr
3. monitor the autoscaler logs

### Steps to Reproduce

_No response_

### Expected behavior

_No response_

### Environment

_No response_

Reproduce the issue by defining one metric name, updating it in the CR, applying the CR, and monitoring the autoscaler logs. Start by tracing how the autoscaler reads and retains CR metrics in memory; done means the updated metric name is reflected correspondingly in the autoscaler logs.

Written by the indexing model from the issue text.