Storage (GB) in Space settings is not always pre-filled

### Product Version

- [ ] Amazon SageMaker Studio Classic
- [X] Amazon SageMaker Studio
- [ ] Issue is not related to SageMaker Studio

### Issue Description

Storage (GB) in Space settings is sometimes empty when preparing to launch a JuypterLab app

### Expected Behavior

Default value always set (e.g., the minimum)

### Observed Behavior

Error: EBS Storage Volume is too low. The minimum value is 5 GB

### Product Category

JupyterLab

### Feedback Category

User Interface

### Other Details

_No response_

Reproduce the Amazon SageMaker Studio launch flow for a JupyterLab app and inspect Space settings when the Storage (GB) field is empty. Verify the minimum EBS storage requirement and confirm that the field is consistently pre-filled before launch.

Written by the indexing model from the issue text.