Fix recent apps in appops.

Prior to this fix all apps would disappear from settings->location
15 minutes after the request was first made (even if request
was ongoing).  Tested this out - apps requesting location longer
than the threshold stay in the list, and apps stay in the list exactly
the threshold time after the location request ENDS.

Change-Id: I7d4db25c615df2ec41e93b1b3191ba606d26719d