GC triggering performance optimizations

Copy the correct starting heap size at process init.
Interfaces to set GC/managed heap parameters.

Change-Id: I0154d1523c3cfdb1214ed0315193cbb24704351f
Mms auto-retrieval (1/3): framework

Change-Id: I9b2f76d8cf9d67eddddfdf7737a948eea680329f

It's only porting this http://review.cyanogenmod.org/#/c/26166/
Part 1 of 3