Make ion_device mls trusted.

Allow device node access irrespective
of MLS restrictions. Third party apps
(untrusted_app) domains need access too.

Change-Id: I132b8201bccb1ff31dc0c15a735f81f645c9836d

device.te

@@ -38,7 +38,7 @@ type video_device, dev_type;
 type vcs_device, dev_type;
 type zero_device, dev_type;
 type fuse_device, dev_type;
-type ion_device, dev_type;
+type ion_device, dev_type, mlstrustedobject;
 type gps_device, dev_type;
 type qtaguid_device, dev_type;
 type watchdog_device, dev_type;