Team Calendars : Focus moves inappropriately in the background instead of the modal.

Issue Description

After activating the Calendars link in the header section, a modal appears and the focus moves inappropriately to the background instead of the modal.

Platform: Confluence server

Version: 7.17.0

Steps to Reproduce

1. Launch URL
2. Navigate through the page in the main content area using tabs key.

Screen Recording

Screen Recording 2022-04-11 at 6.57.28 PM.mov

Actual Behaviour

Modal dialog containing information such as the functions "Add existing calendar", "Import calendar" and "Subscribe by URL" do not receive(that becomes available on activating the "Calendar" link respectively). When the modal dialog is displayed on the screen, the keyboard focus moves on the background content. However, the keyboard focus moves on the modal after navigating through the whole page and then the focus moves on the cancel button in the modal, but not on the other contents in the modal. This make the keyboard user as well as assistive technology user unaware about the available content.

Expected Result

Ensure that the keyboard focus moves at the beginning of the modal dialog content when the modal dialog gets displayed on the screen. This will make the user aware of the content and able to use the function with keyboard.

AXQA Ref:AXQA-369