make su an mlstrustedsubject

Otherwise the following denial occurs when I3972f846ff5e7363799ba521f1258d662b18d64e
is present and "adb root" is run.

  <6>[   64.507223] type=1400 audit(1411432079.100:471): avc: denied { connectto } for pid=717 comm="JDWP" path=006A6477702D636F6E74726F6C scontext=u:r:untrusted_app:s0:c512,c768 tcontext=u:r:su:s0 tclass=unix_stream_socket permissive=1
  <6>[   64.507617] type=1400 audit(1411432079.100:472): avc: denied { connectto } for pid=1659 comm="JDWP" path=006A6477702D636F6E74726F6C scontext=u:r:platform_app:s0:c512,c768 tcontext=u:r:su:s0 tclass=unix_stream_socket permissive=1

Change-Id: I1772912b2ca1446b822303ad6ea3154427f8331f
diff --git a/su.te b/su.te
index 73ca514..6870684 100644
--- a/su.te
+++ b/su.te
@@ -5,7 +5,7 @@
   # Domain used for su processes, as well as for adbd and adb shell
   # after performing an adb root command.  The domain definition is
   # wrapped to ensure that it does not exist at all on -user builds.
-  type su, domain;
+  type su, domain, mlstrustedsubject;
   domain_auto_trans(shell, su_exec, su)
 
   # Allow dumpstate to call su on userdebug / eng builds to collect