Encrypted File SYstems project. Enabling EFS security properties.

This change enables persist.security.* flags in the device, allowing oly the system to modify them.
Change is necessary to allow for further progress in the project, as this is an ideal location for access both from the
framework as well as from the recovery mode / transition.

init/property_service.c

@@ -77,6 +77,7 @@ struct {
     { "service.adb.root", AID_SHELL,    0 },
     { "persist.sys.",     AID_SYSTEM,   0 },
     { "persist.service.", AID_SYSTEM,   0 },
+    { "persist.security.", AID_SYSTEM,   0 },
     { NULL, 0, 0 }
 };