sepolicy: Allow init.qcom.sh script to setprop qemu.hw.mainkeys

This change allows init.qcom.rc script to set the property
qemu.hw.mainkeys to 0, which is used to enable soft keys on
devices that don't have hw keys.

Change-Id: I4e3d2504451e63ca1b203d1afe1d061894ecaacd
3 files changed