Based on limited iPhone7 device swarming pool capacity, we need to
increase tasks expiration time to 1 hour.
Bug: chromium:774381
No-Try: true
Change-Id: I66da6c2d5b03ba8c52eead5260b3c244f1df7894
Reviewed-on: https://webrtc-review.googlesource.com/23003
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Edward Lemur <ehmaldonado@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20692}