Describe the bug:
Exceptions cannot be added when the value field validation is executed.

Kibana/Elasticsearch Stack version:

• 7.10.1
• 7.11.0 BC1

Functional Area (e.g. Endpoint management, timelines, resolver, etc.):

• Exceptions

Preconditions:

• To have a rule created
• To have a value list uploaded

Steps to reproduce:

1. Navigate to Security > Detections
2. Click on Manage detection rules
3. Select the rule
4. Click on Exceptions tab
5. Click on Add new exception button
6. Enter a Field i.e. host.name
7. Click on Value
8. Click on the Exceptions modal in order to raise the Value cannot be empty validation
9. As operator select the operator is in list
10. Select as value the uploaded value list

Current behavior:

• The Add Rule Exception button is disabled
• The exception cannot be added

Expected behavior:

• The Add Rule Exception button is enabled
• The exception can be added

Workaround:

• Click on the trash icon
• Add the condition without raising the Value cannot be empty validation