Change heap base address

Moved to 300 MB to allow room for other people who wish to use the
low 1 GB.

Bug: 17671634

(cherry picked from commit 23fb122b57c52ab1db98708a4e15765b46b26405)

Change-Id: Icb2784fc92cb5c46edb6e3a9de2d8383e012a07c
1 file changed