GC triggering performance optimizations

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

Change-Id: I0154d1523c3cfdb1214ed0315193cbb24704351f
Keaguard: enable translucent keyguard by default

currently it is possible to enable it per device over an overlay and it is disabled
by default. Enable it by default but respect general transluscent disable from
device tree. Manta eg disables this feature due of graphical glichtes.

Change-Id: I3579d47ee3bee05719ef357ffcf19c0137b2302f