Cannot view the cost split among namespace children (resources)

[kreddyj]

Describe the bug
In Capacity tab, if we click on a namespace the page displays blank. On further analysis, I was able to find the root cause. The problem is in the query for namespace metrics. Fixing it should resolve this issue.

To Reproduce
Steps to reproduce the behavior:

1. Go to the 'Capacity' tab
2. Click on any namespace in the heatmap
3. See error

Expected behavior
It should show the child resources of Namespace

Screenshots
NA

Environment (please complete the following information):
NA

Additional context
NA