ActivityManager: memoize for performance

isHighEndGfx and isLargeRam are frequently called upon.. isLargeRam very
frequently within the ActivityStack. these aren't going to change after
they're calculated the first time so subject them to a basic memoization.
FTW.

Change-Id: I176089f99ac6c6e4074cb2fde502c729986ea701
Fix DataInputStream leaks

Fix fixes
-In viewstateserializer, try to close before throwing or returning, and throw early if inputstream is null
-other stuff

Change-Id: I7f3b16057582566b82a85841829ff6ed11cd570e
potential GraphRunner leak in camera effects

if the camera FCs while recording effects.. *poof* a tiny leak is born.
so.. we close mRunner onDestroy.

Change-Id: I6a7983f120a03137f545a3cd9bb07ff51a9cd2d7