native: Increase ART heap limit to 192MB for 1024MB RAM devices

 * Needed for Google SetupWizard to start

 * Without this, SetupWizard is compiled by ART on boot
   and runs out of memory (heap) while running, resulting
   in the SetupWizard crashing and blocking boot

Change-Id: Ic5b8caf4352f6d104af9121a09a01adad1c5bcc3
Signed-off-by: Adrian DC <radian.dc@gmail.com>