Improved docs of false positive UI

doc/user/application_security/vulnerabilities/index.md

@@ -20,6 +20,9 @@ vulnerability include:
 - Linked issues
 - Actions log
 
+In GitLab 14.3 and later, if the scanner determined the vulnerability to be a false positive, an
+alert message is included at the top of the vulnerability's page.
+
 On the vulnerability's page, you can:
 
 - [Change the vulnerability's status](#change-vulnerability-status).

doc/user/application_security/vulnerability_report/index.md

@@ -16,7 +16,16 @@ At all levels, the Vulnerability Report contains:
 - Filters for common vulnerability attributes.
 - Details of each vulnerability, presented in tabular layout.
 
-![Vulnerability Report](img/group_vulnerability_report_v14_2.png)
+The **Activity** column contains icons to indicate the activity, if any, taken on the vulnerability
+in that row:
+
+- Issues **{issues}**: Links to issues created for the vulnerability. For more details, read
+  [Create an issue for a vulnerability](../vulnerabilities/index.md#create-an-issue-for-a-vulnerability).
+- Wrench **{admin}**: The vulnerability has been remediated.
+- False positive **{false-positive}**: The scanner determined this vulnerability to be a false
+  positive.
+
+![Example project-level Vulnerability Report](img/project_level_vulnerability_report_v14_5.png)
 
 ## Project-level Vulnerability Report