Add selinux rules for additional file contexts in userdebug

These rules allow the additional tracepoints we need for running traceur
in userdebug builds to be writeable.

Bug: 37110010
Test: I'm testing by running atrace -l and confirming that the
tracepoints that I'm attempting to enable are available.

Change-Id: Ia352100ed67819ae5acca2aad803fa392d8b80fd