SAML session expiration modal is not shown

In group and project page that have SAML group enabled, we show a banner when the SAML session has expired. However, there are reports that the modal is not showing.

A preliminary investigation has found two potential causes:

• backend The SAML session expires way before the time_remaining_ms returned in the response from /-/user_settings/active_sessions/saml.json. For example, first time I sign into https://gitlab.com/gitlab-com/ops-sub-department/section-ops-request-for-help/-/pipelines, I get a value for time_remaining_ms of 86400000, 24 hours in milliseconds, but it probably expires after 12 hours, or so.
• frontend setTimeout for inactive tabs seems to not be working, hence, it doesn't show the modal.

This issue is track the frontend part.