Modify metrics example to export via OTLP to telemetry.googleapis.com #800

Job	Run time
Shadow Jar Build (Java 11)	2m 19s
Stylecheck (root)	1m 11s
Stylecheck (examples/instrumentation-quickstart)	41s
Test (examples/instrumentation-quickstart, java-11)	14s
Test (root, java-11)	10s
	4m 35s

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