Push Hooks have X-Gitlab-Event: System Hook

Summary

The webhook always sets X-Gitlab-Event: System Hook regardless of what the event is.

The json body identifies the event name as "push": { "object_kind": "push", "event_name": "push", ...

It seems to me that the X-Gitlab-Event header ought to be "Push Hook" for push events.

Steps to reproduce

1. Set up a web hook
2. Push a commit
3. Edit the web hook
4. Notice that the trigger is listed as "System Hook" for the event.
5. View details
6. Notice that X-Gitlab-Event is set to "System Hook" and that event_name is "push"

What is the current bug behavior?

X-Gitlab-Event is set to "System Hook" for push events

What is the expected correct behavior?

X-Gitlab-Event should be set to "Push Hook" for push events

Results of GitLab environment info

Running the omnibus image, gitlab version 12.7.5