[Security Solution] User able to add an exception from ML generated alerts

[MadameSheema]

Kibana version:

• 7.9.0

Elasticsearch version:

• 7.9.0

Describe the bug:
Bug reported by @aarju

I found a small UI bug in the Exceptions workflow today when dealing with ML based rules. When looking at an ML based detection the ‘exceptions’ tab is greyed out but if I click the … next to a detection it opens the exceptions menu for me. After applying the exception it says it is applied but I have no way of viewing whether it is actually applied or not.

Preconditions:

• To have a ML rule created with

Steps to reproduce:

1. Navigate to Security > Detections
2. Click on the 3 dots to expand the rule actions
3. Click on Add rule exception

Current behaviour:

• You are able to add an exception

Expected behavior:

• You should not be able to add an exception

[elasticmachine]

Pinging @elastic/siem (Team:SIEM)

[randomuserid]

Why shouldn't a user be able to add an exception to an ML rule? Isn't this a valid workflow for signal / noise tuning purposes?

[spong]

This is temporary @randomuserid, as we just weren't able to provide support for exceptions w/ ML Rules as part of the initial dev effort of exceptions. I've created #75820 for adding support, and we can remove these checks/guards once supported.