Only auditallow unlabeled accesses not allowed elsewhere.

https://android-review.googlesource.com/#/c/95900/

 added further
unlabeled rules for installd and added explicit unlabeled rules for
vold and system_server.  Exclude these permissions from the auditallow
rules on unlabeled so that we only see the ones that would be denied if
we were to remove the allow domain rules here.

Change-Id: I2b9349ad6606bcb6a74a7e67343a8a9e5d70174c
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>