Add low memory device version of sched scenario group

replaced hackbench01 with hackbench01_low_mem in sched_low_mem

Original hackbench01 test case will run out of memory in android devices with low memory.
This script is created as a light version to the orignal sched test group for low memory devices.
On VTS scheduling, low memory device is determined through checking for system property 'ro.config.low_ram' and VTS will automatically use this script instead of original sched script if the property is set to be 'True' or 'true'

Bug: 63694670
Test: run vts-kernel
Change-Id: Ia5341765b9ac39bccaa8a7045eb543d7b361a8c5
(cherry picked from commit 47e8e7ba692ef873342cb9734e5b19b5dc74482d)
1 file changed