Readd support for metrics

[JCash]

trafficstars

We want to hook up our metrics to a server again.

[britzl]

Related: https://github.com/defold/extender/issues/218

[ekharkunov]

In split-docker branch was added sending metrics to Stackdriver. Here is overview after adding integration and running test builds:

Metric	Is tracked	Notes
job.receive	✅
job.requestSize	⛔
job.sdkDownload	✅
job.sdk	✅
job.gradle.download	✅
job.gradle.cacheSize	⛔
job.cocoapods.install	⛔	MacOS instance doesn't send metrics to Stackdriver now
job.build	✅
job.remoteBuild	✅	Need small fix to track right time because build_async works in thread
job.zip	✅	Not all instances tracked metrics. Only emsdk-3155, winsdk-2022
job.zipSize	✅	Not all instances tracked metrics. Only emsdk-3155, winsdk-2022
job.write	✅
job.cache.upload	✅
job.cache.uploadSize	✅	All zeroes (cache not enabled now)
job.cache.download	✅
job.cache.downloadSize	✅	All zeroes (cache not enabled now)
gauge.service.sdk.get	✅	Select "count time series" in dashboard
gauge.service.gradle.get	✅
counter.service.sdk.get.download	✅
counter.service.sdk.get	✅