Fix/improve procstats association data & printing

- Fix some bugs in how we compute association data.
- Add in overall time for an association, since you can't
  tell that from the time of its individual sources.
- Fix issues in printing data filtered by package/process
  to better select the data.
- Sort the association and source data by active time, so
  the ones with the most impact are first.
- And sort associations by process so that in apps with
  multiple processes (ahem GmsCore), you can tell what is
  going on for each process separately.

Bug: 142283699
Test: manual
Change-Id: I504bd1a0614fce4f4410f3f53993af5cbd576b79