Merge branch 'docs/ref-initial-root-password-for-default-password' into 'master'

Reference /etc/gitlab/initial_root_password for default password

See merge request gitlab-org/gitlab!73301

doc/install/aws/manual_install_aws.md

@@ -671,8 +671,13 @@ That concludes the configuration changes for our GitLab instance. Next, we'll cr
 ### Log in for the first time
 
 Using the domain name you used when setting up [DNS for the load balancer](#configure-dns-for-load-balancer), you should now be able to visit GitLab in your browser.
-If you didn't change the password by any other means, the default password will be the same as the instance ID. To change the default password, login as the `root` user
-with the default password and [change it in the user profile](../../user/profile#change-your-password).
+
+Depending on how you installed GitLab and if you did not change the password by any other means, the default password is either:
+
+- Your instance ID if you used the official GitLab AMI.
+- A randomly generated password stored for 24 hours in `/etc/gitlab/initial_root_password`.
+
+To change the default password, log in as the `root` user with the default password and [change it in the user profile](../../user/profile#change-your-password).
 
 When our [auto scaling group](#create-an-auto-scaling-group) spins up new instances, we'll be able to log in with username `root` and the newly created password.