Stores long-term histogram, outlier information

Moves analysis and storage from NBLog to
PerformanceAnalysis. Applies peak analysis to
outlier information to detect changes in the
distribution of outlier frequency.
Adds cleanup, documentation, FIXME comments for
upcoming changes.

Test: dumpsys media.log

Change-Id: Iea393dac62959aef754ae2a9b4afe2556c1f3ecb