Work on issue #36891897: Need to ensure foreground services...

...can't hide themselves

Tune the policies for when we tell about apps running in the
background after their services have stopped.

- If it ran while the screen was on, the time we require for it
to be running is much shorter (a couple seconds) as well as the
time we tell about it having run (with another tunable for the
minimum time we tell about this).

- If it has only run while the screen is off and stops a sufficient
amount of time before the screen goes on (currently a second) then
we will not show anything when the screen goes on.

- If it stops when the screen turns on, we will make sure the user
sees about it for a short period of time (currently 5 seconds).

Also includes some improved debug output about handler message
queues.

Test: manual

Change-Id: Iab438410d7182b2dfe4f9c1cce7069b26b34834c