ActivityManagerService: Fix heavy games kill during incoming call

Force heavy apps penalisation only to large "cached" apps. Donot
include "previous" app in this category. This ensures large apps
are not killed during special incoming alerts like incall, sms.

Change-Id: I51b4a238415efad63ef36f7e0cd056823a72a47d
Prevent killing of process during service bringup

ActivityManagerService sometimes kills the process whose service
is being brought up during bindService.
This happens when the process starts hitting some Pss threashold.
Specifically this is causing InCallUI process to be killed during
bind request from Phone app.

CRs-Fixed: 681329

Change-Id: Id548a22d7e7ce3aa0b0511763078f813fafd6e16