[BUG] Update observability in url validation

[joshuali925]

Describe the bug
Observability plugin url changed from observability to observability-dashboards, the reporting validation is still expecting observability.

In-context menu validation will fail and user won't be able to download notebook reports within menu, although they are still able to create and download notebook reports in reporting UI as a workaround.

To Reproduce
Steps to reproduce the behavior:

1. Create a notebook in observability plugin
2. Click on "Reporting actions"
3. Click on "Download PDF" and "Download PNG", network requests will fail with [query_url]: invalid relative url
4. Click on "Create report definition" button still works

Expected behavior
All buttons should work

Plugins
Please list all plugins currently enabled.

Screenshots
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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

[peternied]

@joshuali925 I am not familiar with the feature, please add repro steps to the template so we can get a sense of the severity of this issue.

[joshuali925]

@joshuali925 I am not familiar with the feature, please add repro steps to the template so we can get a sense of the severity of this issue.

@peternied updated