logdog/collector: Be forgiving about Put errors.
logdog/collector: Be forgiving about Put errors.

If the Collector encounters a non-transient Put error, it will destroy
the data. Update the transience criteria for Put to be more forgiving of
configuration errors or temporary service (e.g., authentication)
failures.

BUG=None
TEST=None

Review-Url: https://codereview.chromium.org/2869473003

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