[isolate] Support CAS in `isolate batcharchive`
[isolate] Support CAS in `isolate batcharchive`

Bug: 924625
Change-Id: Iba1c798c6e116529ddc828ddc2f5dccff44f938f
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2328248
Reviewed-by: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>
Commit-Queue: Ye Kuang <1cd89f22f3967fc3dcb883b53940be4b98ec483f@google.com>

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