Add additional logic to handle cases when a MetricDescriptor is already defined
on the server, fix an NPE in related code, and add additional tests to ensure
that TimeSeries created from native MetricPoints are well-formed.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=130555708
This change enforces URL-like metric names to match the behavior of
Stackdriver. The StackdriverWriter no longer prepends a slash, which was a
crutch.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=130537347