Add 3GB dalvik heap and hwui memory

Should be used on devices with 3gb's of ram (Bacon, LG G3, etc)
Change-Id: I5833a19ea77b99009fc9f9c7c2a967b0dde06b77
Fix a null dereference.

Change-Id: I7224c3368ff414620062bc08b80a6a94d55d7931
Initialize ARect fields in default ctor

 So that we can use Rect() for update and such.

Bug: 18095940
Change-Id: I03ed87121d2d279f22013b75e95dd7254551ca1f