Create data view - issues with index pattern and matching sources

[jovana-andjelkovic]

Describe the bug:
When creating a data view and entering in an index pattern if you enter a value that should return no indexes the "Matching sources" tab on the right will still display Indexes

Steps to reproduce:

1. Click Create Data view
2. Enter in a non-matching index pattern
3. All index patterns show as matching sources

Expected behavior:
I would expect that the All sources tab has all my indexes and matching sources would show 0.

Screenshots (if relevant):

Any additional context:
This was an issue recorded as part of Serverless bug bash: https://github.com/elastic/UX/issues/164

My assumption is that this is not a bug, but rather an unintuitive experience, as we do update the callout message to reflect if there are any matches. We should investigate if this is a bug, or a need for UX improvement.

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)