Previously, the SW would wait to become idle before executing scheduled
tasks (including checks for newer app versions). It was considered idle
when it hadn't received any request for at least 5 seconds. As a result,
if the app performed polling (i.e. sent requests to the server) in a
shorter than 5 seconds interval, the SW would never detect and update to
a newer app version.
Related issue: #40207
This commit fixes this by adding a max delay to `IdleScheduler` to
ensure that no scheduled task will remain pending for longer than the
specified max delay.
PR Close#40234