Steps to reproduce (assumes ChromeVox or similar)

1. Open https://elastic.github.io/eui/#/guidelines/modals in a new tab.
2. Tab through the navigation to the main content pane.
3. Tab to the "Show Component Code" button and press enter
4. Tab to the first "Show Modal" button
5. Press enter

Actual Result

The "Show Modal" button remains focused and the modal opens in front of the focused button

Expected Result

The "Save" button is auto-focused.

Category: #699: Elastic UI Modals Accessibility
Relevant WCAG Criteria: 3.2.2 Predictable on Input