Add soft timeout to Swift functional tests

If a change breaks the Swift functional tests so that they hang, the
job times out and gets killed. Unfortunately, this means that Swift's
logs aren't captured, so the submitter can't tell what broke.

This commit adds a 30-minute timeout to each of the two functional
test runs (v1 and v2 auth) so that logs will be captured even in case
of a hang. The functional tests normally take 5 minutes or less, so 30
should leave plenty of wiggle room.

Change-Id: I4cde6331b8883ad3bee9b3e9d0c140ed16da476e
Merge "Add soft timeout to Swift functional tests"