Snapshot Retention Policy allows selection for negative number of snapshots

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Environment:
Elasticsearch: 7.5.0 BC 5
Kibana 7.5.0 BC 5
Browser: All

Steps to reproduce:
1.) Start or edit a snapshot policy
2.) On step 3 (snapshot retention), select negative numbers for any of the fields.
3.) Click Next
Expected Result:
The client side validation validates that the number of days and the number of snapshots cannot be configured to a negative number.

Actual Result:
Values are accepted and you move to the next page where the erroneous values are displayed. Still no validation. Doesn't get validated until you hit save and ES validates on the server.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

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/cc @alisonelizabeth

[ffknob]

Here is my attempt on this: #51295

I just set the EuiFieldNumber prop min to 0 so the user cannot use the arrow controls to get to a negative number, but I also had to prevent entering manually the - symbol.

[alisonelizabeth]

Fixed via #51295. Thanks @ffknob!