Make TOP_SLEEPING procstate more like a cached process.

When an app is on the top of the activity stack but the screen
is not on, this doesn't really count as a top app in the normal
sense.  In particular, we'd really like to apply the normal
restrictions we have on background and cached apps: no network
access, no ability to use wake locks, etc.  (In other words, in
this state the app's activity is stopped, so from its perspective
it is no different than the user leaving it to go to another app.)

To do this, we change the order of the TOP_SLEEPING proc state
out from the range of foreground states down to between the
cached and background states.

Test: ActivityManagerProcessStateTest
Bug: 70808931
Change-Id: I994caba8c27553a452de75efa358be0e683d046f