[resultdb] Increase upload freq
[resultdb] Increase upload freq

Currently ResultSink does not upload anything until it 10s passes or we
accumulate 400 test results. This is not very snappy.
Increase the hardcoded frequency. We can tune it more later.

R=1dcb292530f82960316cb3d87cd67c3f212b79cb@chromium.org

Change-Id: I74421fc0770c502217e19c3adc0138279ab163cd
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2251082
Commit-Queue: Scott Lee <1dcb292530f82960316cb3d87cd67c3f212b79cb@chromium.org>
Reviewed-by: Scott Lee <1dcb292530f82960316cb3d87cd67c3f212b79cb@chromium.org>
Auto-Submit: Nodir Turakulov <ef4933a197ef7b4b3f55f1bec4942aead3637a2a@chromium.org>

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