Override "glm_source" param in trail path

What does this MR do and why?

Related issue: #2928 (closed)

1. Override the glm_source parameter in trail link, change from gitlab.com to jihulab.com
2. Stop skipping ee/spec/requests/trials_controller_spec.rb because Upstream MR has fixed it

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Manually delete the judgment statement so that the options can be displayed on the page

diff --git a/jh/app/views/layouts/header/_start_trial.html.haml b/jh/app/views/layouts/header/_start_trial.html.haml
index af694359c7a1..cd68d98a50cf 100644
--- a/jh/app/views/layouts/header/_start_trial.html.haml
+++ b/jh/app/views/layouts/header/_start_trial.html.haml
@@ -1,4 +1,4 @@
-- return unless trials_allowed?(current_user)
+-# - return unless trials_allowed?(current_user)
 - host = URI.parse(::Gitlab::Saas.com_url).host
 
 %li

2. Visit http://127.0.0.1:3000
3. Click the user avatar in the upper right corner to view the link information in the drop-down list

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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