Allow adbd to communicate with surfaceflinger over pipe.

Address the following denials:
[  262.572927] type=1400 audit(1440705761.795:270): avc: denied { read } for pid=237 comm="Binder_2" path="pipe:[14501]" dev="pipefs" ino=14501 scontext=u:r:adbd:s0 tcontext=u:r:surfaceflinger:s0 tclass=fifo_file permissive=1
[  262.573839] type=1400 audit(1440705761.795:271): avc: denied { write } for pid=237 comm="Binder_2" path="pipe:[14502]" dev="pipefs" ino=14502 scontext=u:r:adbd:s0 tcontext=u:r:surfaceflinger:s0 tclass=fifo_file permissive=1

Bug: 23569476
Change-Id: Idf4d2008aa4960c07d1acd9c72388a62c6c30ac4
diff --git a/sepolicy/adbd.te b/sepolicy/adbd.te
new file mode 100644
index 0000000..1d57b2b
--- /dev/null
+++ b/sepolicy/adbd.te
@@ -0,0 +1,2 @@
+allow adbd graphics_device:dir search;
+allow adbd surfaceflinger:fifo_file rw_file_perms;