Instance-level dashboard CSS is uncentered for unconfigured state and project selection

Summary

Instance-level dashboard CSS is uncentered for unconfigured state and project selection

Steps to reproduce

1. Navigate to the instance-level security dashboard
2. Click the Edit Projects button

Example Project

https://gitlab.com/-/security

What is the current bug behavior?

The unconfigured state and project selection are not centered

What is the expected correct behavior?

The unconfigured state and project selection are centered

Relevant logs and/or screenshots