perf: Change heapminfree

The 1GB heap setting is having a heapminfree
value of 512k. This is not correct, and changed
to 2m in line with KK settings.

This change reduces GC significantly during app
launch on L, there by improving the first launch
latency.

CRs-Fixed: 774352

Change-Id: I701e429d59b3a2d8cccc4b87649ae866f4d78612