Fix issue #25357209: Could not send SMS or MMS messages, had to reboot

I think what probably happened is that since we only report an app
going in to the "interaction" state as an interaction event to usage
stats, apps that sit around in that state forever will only see one
interaction at the start and never again.  So usage stats could start
thinking they are idle.

Fix this by having the activity manager report an interaction event
for such long running applications at least once a day.

Also, because it is correct and for paranoia by protected us another
way, system uids should never go in to standby.

Change-Id: I8a3805bfca86cbe78560488a649ecd07427da99a