Media Metrics for NuPlayer, Codec, Extractor

Collect metrics for nuplayer/mediaplayer, codec, extractor.
publishes them to media.metrics service
provides hooks that local APIs use to connect to retrieve metrics
from the above when running on their behalf.

Separate set of changes does the final hop to the local APIs.

Bug: 34715803
Test: build & run, observed code/extractor/player metrics in logs
Change-Id: Ic5a0a7b3b93a5a41af93d81050ba038f0f7a4329