Grant create_file_perms to hal_usb_gadget_server

type=1400 audit(1516839845.731:13): avc: denied { unlink } for pid=800
comm="usb@1.1-service" name="UDC" dev="configfs" ino=27143
scontext=u:r:hal_usb_impl:s0 tcontext=u:object_r:configfs:s0
tclass=file permissive=0

avc: denied { unlink } for pid=800 comm="usb@1.1-service" name="UDC"
dev="configfs" ino=27143 scontext=u:r:hal_usb_impl:s0
tcontext=u:object_r:configfs:s0 tclass=file permissive=0


Bug: 63669128
Change-Id: If193c88658ec9c72299beb717990ddb8211da9a5