Remove system_server and zygote unlabeled execute access.

Now that all of /data outside of /data/data should be labeled
even on legacy devices as a result of
Ib8d9751a47c8e0238cf499fcec61898937945d9d, there
should be no reason to permit the system_server or zygote
execute access to unlabeled files.

This is the only remaining case where a type writable by
app domains can be executed by system services, so eliminating
it is desirable.

That said, I have not specifically tested the non-SE to SE
upgrade path to confirm that this causes no problems.

Change-Id: Ie488bd6e347d4a210806a3308ab25b00952aadb4
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

system_server.te

@@ -236,11 +236,6 @@ allow system_server fscklogs:file unlink;
 # For SELinuxPolicyInstallReceiver
 selinux_manage_policy(system_server)
 
-# For legacy unlabeled userdata on existing devices.
-# See discussion of Unlabeled files in domain.te for more information.
-# This rule is for dalvikcache mmap/mprotect PROT_EXEC.
-allow system_server unlabeled:file execute;
-
 # logd access, system_server inherit logd write socket
 # (urge is to deprecate this long term)
 allow system_server zygote:unix_dgram_socket write;

zygote.te

@@ -52,8 +52,3 @@ allow zygote ashmem_device:chr_file execute;
 allow zygote shell_data_file:file { write getattr };
 allow zygote system_server:binder { transfer call };
 allow zygote servicemanager:binder { call };
-
-# For legacy unlabeled userdata on existing devices.
-# See discussion of Unlabeled files in domain.te for more information.
-# This rule is for dalvikcache mmap/mprotect PROT_EXEC.
-allow zygote unlabeled:file execute;