Add latest changes from gitlab-org/gitlab@12-8-stable-ee

CHANGELOG-EE.md

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+## 12.8.2
+
+### Security (5 changes)
+
+- Don't show Contribution Analytics to users who are not group members.
+- Update epic tree when group is transfered.
+- Fix Service Side Request Forgery in JenkinsDeprecatedService.
+- Enforce vulnerability feedback pipeline is in the same project.
+- Enforce existing vulnerability feedback pipeline is in the same project.
+
+
 ## 12.8.1
 ### Performance (1 change)