Log deferred jobs metrics to batterystats

Log the deferred jobs event count, number of deferred jobs,
time since last job execution and break those down into
different time-since buckets in case the average becomes
too noisy.

Bug: 70297451
Test: dumpsys batterystats --checkin

Change-Id: Iafad6137989246f203a623ce1511140d4eac35b0