Add HAR to spelling exceptions

What does this MR do and why?

Adds HAR to doc/.vale/gitlab/spelling-exceptions.txt and doc/.vale/gitlab/Uppercase.yml

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doc/administration/settings/jira_cloud_app_troubleshooting.md

@@ -131,7 +131,7 @@ Provide GitLab Support with:
 - Optional. [A HAR file](https://support.zendesk.com/hc/en-us/articles/4408828867098-Generating-a-HAR-file-for-troubleshooting)
   you've processed with [`harcleaner`](https://gitlab.com/gitlab-com/support/toolbox/harcleaner) that captures the problem.
 
-The GitLab Support team can then look up why this is failing in the GitLab.com server logs.
+GitLab Support can then investigate the issue in the GitLab.com server logs.
 
 #### GitLab Support