Add MediaMetrics support to MediaParser

Includes:
- Java changes to collect the metrics.
- JNI changes to plumb metrics to the MediaMetrics service.
- statsd atoms.proto changes for data transmission.

Bug: 158742256
Test: atest CtsMediaParserTestCases
Test: atest CtsMediaParserHostTestCases
Test: Manually using dumpsys.
Change-Id: If51ee018da3056231910cd9c18f1b938a5c0e343
Merged-In: If51ee018da3056231910cd9c18f1b938a5c0e343