Add passive_metrics USE flag to platform2

We want to be able to control the inclusion of the metrics_daemon,
which passively gathers power stats and the like and sends them
through the UMA pipeline iff the user has opted-in to metrics

CQ-DEPEND=CL:177244, CL:177291
TEST=emerge platform2 with USE='-passive_metrics' on and off, with and without FEATURES=test

Change-Id: Id6af84d3de585a156d8ebbcc23117df000de080d
Reviewed-by: Chris Masone <>
Tested-by: Chris Masone <>
Commit-Queue: Chris Masone <>
1 file changed
tree: e98b89572e4c6319c30368683fe49ba490f4c2ff
  1. metrics/