cas: log more time stats
cas: log more time stats

This is to see more number in the task like
https://chromium-swarm.appspot.com/task?id=52973ff7542c0610

Bug: 1172879
Change-Id: I97b3cd8d8bee2e08b94009124ee2dc4822748747
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2794261
Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Commit-Queue: Yoshisato Yanagisawa <5d95c5c75e3d691d9c77888fff4498e04f8b7157@google.com>
Auto-Submit: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Reviewed-by: Yoshisato Yanagisawa <5d95c5c75e3d691d9c77888fff4498e04f8b7157@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go