appops: Implement concept of delayedcount.

 High frequency request ops will be delayed until their ignore count
 ceiling is met. This is to mitigate the overloading the main activity
 manager service handler and having watchdog kill our service.

 Google play services likes to share its uid with numerous packages to avoid
 having to grant permissions from the users perspective and thus is the worst
 example of overloading this queue -- so, to not encourage bad behavior,
 we move them to the back of the line. NOTE: these values are magic, and may need
 tuning. Ideally we'd want a ringbuffer or token bucket here to do proper rate
 limiting.

Change-Id: I5c3e88807abc80f9700dd68dcecd87dac4626de7
TICKET: CYNGNOS-2869
(cherry picked from commit b4088dd1)