Remove ConnectivityService#PerUidCounter hack

Follow up from aosp/1781202 and aosp/1821293, creating nris
before removing old nris had been proven not necessary for
per-app API flow. Hence, the per-uid counter hack for system
uid that allows counter temporary go over limit does not
actually be used in the production code.

In other words, this CL is a no-op refactoring.

Test: testRequestCountLimits
Bug: 235771502
Change-Id: I8f71c6e4506fbec60cb503731aee64ab022b4634
1 file changed