Move mac_permissions to etc/selinux

Test: Build and boot Marlin
Test: See the following in the logs:
01-01 02:10:28.756  1345  1345 D SELinuxMMAC: Using policy file /system/etc/selinux/plat_mac_permissions.xml
01-01 02:10:28.787  1345  1345 D SELinuxMMAC: Using policy file /vendor/etc/selinux/nonplat_mac_permissions.xml
Bug: 36003167

Change-Id: I97479260eabe14c1b1dcc238d7322016f6b5c4dd
1 file changed