The bug fix is in the readEvents() wrapper, but also make sure that
both the Event and LogReader interfaces only expose milliseconds.
No test changes, because the Java-layer didn't change, the bug was
in the JNI wrapper, below the level that's easily testable.
Bug: 37205954
Test: runtest --path frameworks/base/core/tests/coretests/src/android/metrics
Change-Id: I0c4ad9233a81bcf585ab525b3a5cc63fbb645093
5357e642bc