Update the Security Finding class by changing the activity_id enum label

[pagbabian-splunk]

The Security Finding class has the following enum:
0 - Unknown
1 - Generate
2 - Update
99 - Other

Generate appears to be equivalent to Create which is used frequently throughout the schema.

This proposal changes Generate to Create.

Note, it is technically NOT a breaking change, however by convention the optional value populated in activity_name would change from "Generate" to "Create"

[irakledibm]

"Create" makes sense to me. I would probably add "Close" as well.