Changes to a much more efficient and more reusable protobuf format for
metrics.
Test: Widevine tests, Google Play and MediaDrm CTS test.
Bug: 73724218
Change-Id: I3299051d7a16bcd7758c8f272415ca40e10c1313
This is part one of a mult-part change to revise some metrics. Several
metrics are currently EventMetric type when they should be a simpler
type.
Test: Added unit tests for the new types. Also, re-ran existing tests.
Verified playback works with Google Play, and re-ran Widevine GTS tests.
Bug: 36220619
Change-Id: I2ec8fc355f66ad4834dd722aacd22541fb9c94ad